Antifouling paint composition

Abstract

Provided is an antifouling coating composition which, when held in seawater over a long period of time, retains a stable coating film dissolution rate without causing coating film problems such as cracking and can sustain stable antifouling performance.　The present invention provides an antifouling coating composition that comprises a copolymer A and an antifouling agent D, wherein: the copolymer A is a copolymer of a monomer (a) represented by general formula (1) with an ethylenically unsaturated monomer (b) other than the monomer (a); the monomer (a) includes a compound in which n in general formula (1) is 2 or more; the monomer (b) includes a monomer (b1); and a homopolymer of the monomer (b1) has a glass transition temperature (Tg) of -20°C or higher and a common logarithm logP of the n-octanol / water partition coefficient P of 0.9 or less.

Description

[Technical Field]

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

[0002] Aquatic fouling organisms such as barnacles, serpula, mussels, bryozoans, sea squirts, green laver, sea lettuce, slime, etc. 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 function of these ships and damaging their appearance. 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 providing antifouling performance over a long period of time (Patent Documents 1 to 4).

[0003] 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 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). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 63-61989 [Patent Document 2] Japanese Patent Application Laid-Open No. 2003-119420 [Patent Document 3] Japanese Patent Application Laid-Open No. 2003-119419 [Patent Document 4] Japanese Patent Application Laid-Open No. 2002-3776 [Patent Document 5] WO2020 / 045211 publication Summary of the Invention [Problem to be solved by the invention]

[0005] Although the antifouling coating film made from the antifouling coating composition described in Patent Document 5 has improved coating film solubility, etc., when immersed in seawater for an extended period of time, the coating film may dissolve excessively or may develop abnormalities in the coating film such as cracks, and further improvements are required.

[0006] The present invention has been made in view of the above circumstances, and provides an antifouling coating composition that can maintain a stable coating film dissolution rate in seawater over a long period of time, and can maintain stable antifouling performance without causing coating film abnormalities such as cracks. [Means for solving the problem]

[0007] According to the present invention, there is provided an antifouling coating composition containing copolymer A and antifouling agent D, wherein said copolymer A is a copolymer of monomer (a) represented by general formula (1) and an ethylenically unsaturated monomer (b) other than said monomer (a), said monomer (a) comprises a compound in which n in said general formula (1) is 2 or more, said monomer (b) comprises monomer (b1), and said monomer (b1) has a homopolymer glass transition temperature (Tg) of -20°C or higher and a common logarithm of the n-octanol / water partition coefficient P, logP, of 0.9 or less.

[0008] As a result of extensive research into solving the above problems, the present inventors have found that a composition containing copolymer A and antifouling agent D can solve the above problems, and have thus completed the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] The present invention will be described in detail below. 1. Antifouling paint composition The antifouling coating composition of the present invention contains copolymer A and antifouling agent D.

[0010] 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%, and specifically, for example, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, or 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.

[0011] 1-1-1. Monomer (a) The monomer (a) is represented by the general formula (1).

[0012] [ka] 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 alkoxy group having 1 to 8 carbon atoms or an alkyl group having 1 to 8 carbon atoms which may be substituted with a phenyl group, or represents a phenyl group; and n represents an integer of 1 to 10.

[0013] R 2 is preferably hydrogen or a methyl group.

[0014] R 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. 3 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.

[0015] 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.

[0016] Monomer (a) includes a compound in which n is 2 or more in general formula (1). When monomer (a) contains a compound in which n is 2 or more, coating film solubility is increased. 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.

[0017] 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 easily deteriorated after 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.

[0018] <Monomer (a1)> The monomer (a1) is a compound in which n is 1 in the 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,

[0044] 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 preferred examples include 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.

[0019] <Monomer (a2)> The monomer (a2) is a compound in which n in the general formula (1) is at least 2. n in the general formula (1) is preferably 2 to 6 from the viewpoint of long-term antifouling properties.

[0020] 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.

[0021] Examples of the monomer (a2) include methyl di(oxycarbonylmethyl) (meth)acrylate, ethyl di(oxycarbonylmethyl) (meth)acrylate, isopropyl di(oxycarbonylmethyl) (meth)acrylate, n-propyl di(oxycarbonylmethyl) (meth)acrylate, n-butyl di(oxycarbonylmethyl) (meth)acrylate, t-butyl di(oxycarbonylmethyl) (meth)acrylate, 2-ethylhexyl di(oxycarbonylmethyl) (meth)acrylate, cyclohexyl di(oxycarbonylmethyl) (meth)acrylate, 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) (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 poly(oxycarbonylmethyl) (meth)acrylate, n-propyl poly(oxycarbonylmethyl) (meth)acrylate, n-butyl poly(oxycarbonylmethyl) (meth)acrylate, t-butyl poly(oxycarbonylmethyl) (meth)acrylate, 2-ethylhexyl poly(oxycarbonylmethyl) (meth)acrylate, cyclohexyl poly(oxycarbonylmethyl) (meth)acrylate, benzyl poly(oxycarbonylmethyl) (meth)acrylate, phenyl poly(oxycarbonylmethyl) (meth)acrylate, 2-methoxyethyl poly(oxycarbonylmethyl) (meth)acrylate, 4-methoxybutyl poly(oxycarbonylmethyl) (meth)acrylate, allyl poly(oxycarbonylmethyl) (meth)acrylate, vinyl poly(oxycarbonylmethyl) (meth)acrylate, methyl poly[1-(oxypolycarbonyl)ethyl] (meth)acrylate, ethyl poly[1-(oxypolycarbonyl)ethyl] (meth)acrylate, (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 Examples of such poly(oxycarbonylmethyl) (meth)acrylate include methyl poly(oxycarbonylmethyl) (meth)acrylate, ethyl poly(oxycarbonylmethyl) (meth)acrylate, isopropyl poly(oxycarbonylmethyl) (meth)acrylate, n-propyl poly(oxycarbonylmethyl) (meth)acrylate, n-butyl poly(oxycarbonylmethyl) (meth)acrylate, methyl poly(1-(oxypolycarbonylethyl) (meth)acrylate, and ethyl poly(1-(oxypolycarbonylethyl) (meth)acrylate).

[0022] 1-1-2.Monomer (b) Monomer (b) is an ethylenically unsaturated monomer other than monomer (a), and examples thereof include (meth)acrylic acid esters, 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. Monomer (b) can be classified into monomer (b1) and monomer (b2), and the monomer (b) used in the polymerization of copolymer A contains at least monomer (b1).

[0023] <Monomer (b1)> The monomer (b1) is an ethylenically unsaturated monomer having a homopolymer glass transition temperature (Tg) of −20° C. or higher and a common logarithm logP of the n-octanol / water partition coefficient P of 0.9 or lower.

[0024] The glass transition temperature (Tg) of the homopolymer is preferably 0°C or higher, and more preferably 20°C or higher, from the viewpoint of improving the strength and crack resistance of the antifouling coating film. This Tg is, for example, -20 to 300°C, and specifically, for example, -20, 0, 20, 40, 60, 80, 100, 120, 140, 160, 180, 200, 220, 240, 260, 280, or 300°C, and may be within a range between any two of the values ​​exemplified here or higher. The glass transition temperature (Tg) of the homopolymer in this patent is a value measured in accordance with ASTM E1356-08 and refers to the midpoint temperature (Tm).

[0025] The partition coefficient P is the ratio of the partition concentrations of a substance to each phase of a two-phase solvent system consisting of n-octanol and water, and logP is the common logarithm of the partition coefficient P. A smaller logP value indicates higher hydrophilicity (lower lipophilicity). In this specification, logP refers to a value calculated based on Crippen's fragmentation method (J. Chem. Inf. Comput. Sci., 27, 21 (1987)). LogP calculated by this method can be calculated using, for example, PerkinElmer's ChemDraw Professional 17.0 program.

[0026] The log P is preferably 0.8 or less, more preferably 0.6 or less, and from the viewpoint of the water resistance of the coating film, preferably −0.8 or more. Log P is, for example, -0.80 to 0.90, and specifically, for example, -0.80, -0.75, -0.70, -0.65, -0.60, -0.55, -0.50, -0.45, -0.40, -0.35, -0.30, -0.25, -0.20, -0.15, -0.10, -0.05, 0.00, 0.05, 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, 0.50, 0.55, 0.60, 0.65, 0.70, 0.75, 0.80, 0.85, 0.90, and may be within a range between any two of the numerical values ​​exemplified here or equal to or less than any one of them.

[0027] Examples of the monomer (b1) include N-(2-hydroxyethyl)acrylamide (Tg: 98°C, logP: -0.56), 2,3-dihydroxypropyl methacrylate (Tg: 55°C, logP: -0.06), (meth)acrylamide (Tg: 165°C, logP: -0.27), acryloylmorpholine (Tg: 145°C, logP: -0.20), 2-(acetoacetyloxy)ethyl methacrylate (Tg: 9°C, logP: -0.20), and the like. , logP:0.27), mono(2-acryloyloxyethyl) succinate (Tg:-14°C, logP:0.02), N-(3-dimethylaminopropyl)acrylamide (Tg:134°C, logP:0.07), N-(3-dimethylaminopropyl)methacrylamide (Tg:96°C, logP:0.42), 2-hydroxyethyl acrylate (Tg:-15°C, logP:0.12), 2-hydroxyethyl methacrylate (Tg: 55°C, logP: 0.47), N,N'-dimethylacrylamide (Tg: 119°C, logP: 0.20), glycidyl methacrylate (Tg: 46°C, logP: 0.57), N-vinyl-2-pyrrolidone (Tg: 177°C, logP: 0.24), 2-hydroxypropyl acrylate (Tg: -7°C, logP: 0.44), 2-hydroxypropyl methacrylate (Tg: 26°C, logP: 0.79), acetic acid Examples of the monomer (b1) include vinyl (Tg: 28°C, logP: 0.54), methyl acrylate (Tg: 8°C, logP: 0.64), N-isopropylacrylamide (Tg: 134°C, logP: 0.62), tetrahydrofurfuryl acrylate (Tg: -12°C, logP: 0.78), 2-ethoxyethyl acrylate (Tg: 16°C, logP: 0.83), and N,N-diethylacrylamide (Tg: 81°C, logP: 0.87). 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).

[0029] Examples of the (meth)acrylic acid ester as the monomer (b2) include methyl methacrylate (Tg: 105°C, logP: 0.99), ethyl acrylate (Tg: -22°C, logP: 0.98), ethyl methacrylate (Tg: 65°C, logP: 1.33), butyl acrylate (Tg: -54°C, logP: 1.88), butyl methacrylate (Tg: 20°C, logP: 2.23), isobutyl acrylate (Tg: -26°C, logP: 1.86), isobutyl methacrylate (Tg: 48°C, logP: 2.21), t-butyl acrylate (Tg: 14°C, logP: 1.51), t-butyl methacrylate (Tg: 107°C, (meth)acrylic acid esters such as 2-ethylhexyl acrylate (Tg: -85°C, logP: 3.53), 2-ethylhexyl methacrylate (Tg: -10°C, logP: 3.88), lauryl acrylate (Tg: -23°C, logP: 5.22), lauryl methacrylate (Tg: -65°C, logP: 5.57), benzyl acrylate (Tg: 6°C, logP: 2.37), benzyl methacrylate (Tg: 54°C, logP: 2.72), phenyl acrylate (Tg: 57°C, logP: 2.30), and cyclic trimethylolpropane formal acrylate (Tg: 27°C, logP: 1.45); Examples thereof include (meth)acrylic acid silyl esters such as triisopropylsilyl acrylate (Tg: 34° C.) and triisopropylsilyl methacrylate (Tg: 86° C.).

[0030] Examples of the vinyl compound that is the monomer (b2) include vinyl compounds having functional groups such as vinyl chloride (Tg: 87°C, logP: 1.51), vinylidene chloride (Tg: -18°C, logP: 1.79), vinyl benzoate (logP: 1.79), vinyl butyrate (Tg: -5°C, logP: 1.61), butyl vinyl ether (logP: 1.91), and lauryl vinyl ether (logP: 5.25).

[0031] Examples of aromatic compounds that are the monomers (b2) include styrene (Tg: 110°C, logP: 2.67), vinyltoluene (logP: 3.16), and α-methylstyrene (Tg: 168°C, logP: 2.84).

[0032] Examples of the dialkyl ester compound of a dibasic acid, which is the monomer (b2), include dibutyl maleate (logP: 2.65).

[0033] 1-1-3. Properties and manufacturing method of copolymer A The weight-average molecular weight (Mw) of copolymer A is preferably 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.

[0034] The Mw can be measured by, for example, gel permeation chromatography (GPC).

[0035] 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 (b1), and monomer (b2).

[0036] 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.

[0037] 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. A chain transfer agent can also 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.

[0038] 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 because it allows copolymer A to be obtained easily and accurately.

[0039] 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 can be used alone or in combination of two or more. 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, and preferably 60 to 150°C.

[0040] The polymerization reaction is preferably carried out in an atmosphere of an inert gas such as nitrogen gas or argon gas.

[0041] 1-2. Antifouling agent D Antifouling agents include, for example, 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, 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 ethylenebisdithiocarbamate (generic name: zineb), 4,5-dichloro-2-n-octyl-3-isothiazolone (generic name: She-Nine 211), 3,4-dichlorophenyl-NN-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.

[0042] The content of the antifouling agent 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 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.

[0043] 1-3. Other additives Furthermore, if necessary, resin components other than copolymer A, elution modifiers, plasticizers, pigments, dyes, antifoaming agents, dehydrating agents, thixotropic agents, organic solvents, etc. can be added to the resin for antifouling coating materials of the present invention to form an antifouling coating material.

[0044] Examples of other resin components include copolymer B. Copolymer B 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.

[0045] The polymerization method, initiator, solvent, temperature, other conditions, and method for measuring Mw can be the same as those described for Copolymer A.

[0046] The content of copolymer B in the composition of the present invention is not particularly limited, but the mass ratio (copolymer B / copolymer A) of the content to copolymer A, calculated as solid content, is usually 0.1 to 0.9, and 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, or may be within a range between any two of the values ​​exemplified here.

[0047] Examples of the elution modifier include monocarboxylic acids and their salts, such as rosin, rosin derivatives, naphthenic acid, cycloalkenylcarboxylic acid, bicycloalkenylcarboxylic acid, versatic acid, trimethylisobutenylcyclohexenecarboxylic acid, and metal salts thereof, or the above-mentioned 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 commercially available alicyclic hydrocarbon resins include Quinton 1500, 1525L, and 1700 (trade names, manufactured by Zeon Corporation). Of these, rosin, rosin derivatives, naphthenic acid, versatic acid, trimethylisobutenylcyclohexenecarboxylic acid, or metal salts thereof are preferred.

[0048] 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.

[0049] 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, an antifouling agent, other additives, etc., using a disperser. The mixed liquid is preferably one in which copolymer A and various materials such as an antifouling agent are dissolved or dispersed in a solvent. As the dispersing machine, for example, a machine that can be used as a fine grinding machine can be suitably used. For example, a commercially available homomixer, sand mill, bead mill, disperser, etc. can be used. Alternatively, the mixed liquid may be mixed and dispersed using a container equipped with a stirrer and containing glass beads for mixing and dispersion.

[0050] 3. Antifouling treatment method, antifouling coating film, and coated object The antifouling treatment method of the present invention uses the above antifouling coating composition to form an antifouling coating film on the surface of an object to be coated. According to the antifouling treatment method of the present invention, the antifouling coating film gradually dissolves from the surface, allowing the coating surface to be constantly renewed, thereby preventing the adhesion of aquatic fouling organisms. Examples of objects on which a coating film is formed include ships (particularly ship bottoms), fishing equipment, underwater structures, and the like. The thickness of the antifouling coating film may be appropriately set depending on the type of object to be coated, the sailing speed of the ship, the seawater temperature, etc. For example, when the object to be coated is the bottom of a ship, the thickness of the antifouling coating film is usually 50 to 700 μm, and preferably 100 to 600 μm. [Example]

[0051] The following examples will be given to further clarify the features of the present invention, but the present invention is not limited to these examples. In each Production Example, Example, and Comparative Example, % represents % by mass. The weight average molecular weight (Mw) is a value determined by GPC (polystyrene equivalent value). The GPC conditions are as follows. Equipment: Tosoh Corporation HLC-8220GPC Columns: TSKgel SuperHZM-M (2 columns) 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." The logP values ​​in Table 5 were obtained using the ChemDraw Professional 17 Suite program from PerkinElmer.

[0052] 1. Manufacturing example 1-1. Example of production of monomer (a1) <Production Example 1 (Production of Monomer a1-1)> A four-neck 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 while stirring, keeping the temperature below 40°C. After the addition was complete, the mixture was stirred at 70-80°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 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 the reaction 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.

[0053] [Table 1]

[0054] 1-2. Example of production of monomer (a2) <Production Example 4 (Production of Monomer a2-1)> (1st reaction) A four-necked flask equipped with a thermometer, a condenser, and a stirrer was charged with 215 g (1.85 mol) of sodium monochloroacetate, 201 g (1.85 mol) of methyl chloroacetate, and 300 g of N-methyl-2-pyrrolidone, and the mixture was stirred for 6 hours at 70 to 80° C. After completion of the reaction, 500 ml of toluene was charged to 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 distilled off by concentration under reduced pressure, yielding 262 g of methoxycarbonylmethyl chloroacetate.

[0055] (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 (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 while stirring, keeping the temperature below 40°C. After the addition was complete, the mixture was stirred at 70-80°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 230.6 g of monomer a2-1.

[0056] <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 the reaction 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.

[0057] [Table 2]

[0058] 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

[0059] 1-3. Example of copolymer solution production <Production Example P1 (Production of Copolymer Solution A-1)> A four-neck flask equipped with a thermometer, condenser, stirrer, and dropping funnel was charged with 80 g of xylene and 20 g of 1-butanol as solvents, and nitrogen gas was introduced while stirring and maintaining the temperature at 88°C. A mixture of monomers (a1), (a2), (b1), and (b2) in the amounts (g) shown in Table 3, and 2.0 g of 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate (initial addition) as a polymerization initiator, was added dropwise over 3 hours while maintaining the temperature at 88°C. 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 then stirred at the same temperature for another 2 hours and cooled to room temperature to obtain copolymer solution A-1. The heating residue and Mw of A-1 are shown in Table 3.

[0060] <Production Examples P2 to P16 (Production of Copolymer Solutions A-2 to A-13, B-1 to B-3)> Copolymer solutions A-2 to A-13 and B-1 to B-3 were obtained by carrying out the polymerization reaction in the same manner as in Production Example P1, except that the monomers, polymerization initiators, and solvents shown in Tables 3 and 4 were used. 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.

[0061] [Table 3]

[0062] [Table 4]

[0063] Table 5 shows the Tg and logP of the monomer (b) in Tables 3 and 4.

[0064] [Table 5]

[0065] 1-4.Other manufacturing examples <Production Example C1 (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, yielding a xylene solution of gum rosin (brown, transparent liquid, 50% solids). The residual content of the resulting solution was 50.3%.

[0066] <Production Example C2 (Production 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 then added so that all of the resin acids in the rosin would form 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 dark brown, transparent liquid with a solid content of 50%). The residual content of the resulting solution was 50.2%.

[0067] 2. Examples 1 to 13 and Comparative Examples 1 to 3 (Production of Coating Compositions) The components shown in Tables 6 and 7 were blended in the proportions (mass %) shown in the tables, and mixed and dispersed with glass beads having a diameter of 1.5 to 2.5 mm to produce coating compositions.

[0068] [Table 6]

[0069] [Table 7]

[0070] Details of the components in the table are as follows: <Anti-fouling agent> Cuprous oxide: Product name "NC-301" (manufactured by Nisshin Chemco Co., Ltd.) Copper pyrithione: Product name "Copper Omajin" (manufactured by LONZA Corporation)

[0071] <Dissolution modifier> Gum rosin solution: Use the solution prepared in Example C1 Gum rosin zinc salt solution: Use the solution produced in Production Example C2

[0072] <Pigments> Bengala: Product name: "Bengara Gold" (manufactured by Morishita Bengala Kogyo Co., Ltd.) Talc: Product name "Talc MS" (manufactured by Nippon Talc Co., Ltd.) Zinc oxide: Product name "Zinc Oxide Type 2" (manufactured by Seido Chemical Industry Co., Ltd.) Titanium oxide: Product name "FR-41" (manufactured by Furukawa Co., Ltd.)

[0073] <Other additives> Disparlon A603-20X: Amide-based thixotropic agent: Product name "Disparlon A603-20X" (Kusumoto Chemicals Co., Ltd.) Tricresyl phosphate: (manufactured by Daihachi Chemical Industry Co., Ltd.) Tetraethoxysilane: Product name "Ethyl Silicate 28" (manufactured by Colcoat Co., Ltd.)

[0074] 3. Exam All of the coating compositions in 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 6 and 7. In all the comparative examples, the results were not as good as those in the examples in either the rotary test or the antifouling test.

[0075] <Test Example 1 (Rotary Test)> A rotating drum with a diameter of 515 mm and a height of 440 mm was installed in the center of the tank and was rotated by a motor. It was also equipped with a cooling device to keep the seawater temperature constant and an automatic pH controller to keep the seawater pH constant. Test panels were prepared according to the following method. First, an anti-rust paint (epoxy vinyl A / C) was applied to a titanium plate (71 × 100 × 0.5 mm) to a dry thickness of approximately 100 μm, and then dried to form an anti-rust coating film. Then, the coating compositions obtained in the examples and comparative examples were applied to a dry film thickness of approximately 450 μm, and the plate was dried at 40°C for 3 days to prepare a test plate. The test plate was fixed to the rotating drum of the rotating device of the above-mentioned equipment so that it would come into contact with seawater, and the rotating drum was rotated at a speed of 20 knots. During this time, the seawater temperature was kept at 25°C and 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 VK-X100 shape measuring laser microscope. The difference between these measurements was used to calculate the dissolved film thickness to obtain the amount of dissolved film per month (μm / month). The solubility of the film was evaluated according to the following criteria. In addition, when measuring the remaining film thickness after 24 months and 36 months of rotary testing, 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 coating surface condition was evaluated according to the following criteria. ◎: No abnormalities at all ○: Hair cracks are observed on less than 10% of the total coating surface area △: Hair cracks are observed on 10% to less than 30% of the total coating surface area ×: Hair cracks are observed on more than 30% of the total surface area of ​​the coating film. ××: Abnormalities in the coating such as large cracks, blisters, peeling (only the surface or part of the edge of the coating is peeled off), or delamination (the entire coating is peeled off and no test coating remains) -: After the accelerated aging treatment, the paint developed problems such as thickening and gelling, making it impossible to carry out the test.

[0076] <Test Example 2 (Anti-fouling test)> The coating compositions obtained in the Examples and Comparative Examples were applied to both sides of a rigid PVC board (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 produce a test board with a dry coating thickness of approximately 300 μm. This test board was immersed 1.5 m below sea level in Owase City, Mie Prefecture, and the damage to the test board by deposits was observed after 12 months, 24 months, and 36 months. The evaluation was carried out by visually observing the state 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. ○: No fouling organisms such as shellfish or algae are attached, and although there is a thin layer of slime (enough to make the coating surface visible), it can be removed by lightly wiping with a brush. △: No adhesion of fouling organisms such as shellfish or algae, but the slime is so thick that the coating surface is not visible and cannot be removed even by wiping vigorously with a brush. ×: Level of fouling organisms such as shellfish and algae adhering -: After the accelerated aging treatment, the paint developed problems such as thickening and gelling, making it impossible to carry out the test.

Claims

[Claim 1] An antifouling coating composition comprising a copolymer A and an antifouling agent D, 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, The monomer (b) includes a monomer (b1), The monomer (b1) has a homopolymer glass transition temperature (Tg) of −20° C. or higher and a common logarithm (logP) of the n-octanol / water partition coefficient (P) of 0.9 or lower, The antifouling coating composition, wherein the monomer (b1) is acryloylmorpholine, N,N-dimethylacrylamide, N-vinyl-2-pyrrolidone, N-isopropylacrylamide, N,N-diethylacrylamide, 2-hydroxyethyl methacrylate, vinyl acetate, glycidyl methacrylate, acrylamide, or tetrahydrofurfuryl acrylate. 【Chemistry 1】 (In the formula, R １ represents hydrogen or a methyl group, and R ２ represents hydrogen, and R ３ represents a methyl group or an ethyl group, and n represents an integer of 1 to 10.

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