Antifouling paint composition

Abstract

To provide an antifouling coating composition capable of both achieving long-term antifouling properties and crack resistance of a coating film in seawater and freshwater.SOLUTION: There is provided an antifouling coating composition which comprises a silyl ester based polymer (A) and a copolymer (B) having (b-1) a structural unit derived from styrene and (b-2) a structural unit derived from a polymerizable monomer (b2) represented by the formula (b2). Formula (b2): CH2=CH-COO-(Rb1-O)n-Rb2 [wherein, Rb1 is an alkanediyl group having 1 to 5 carbon atoms, Rb2 is an alkyl group having 1 to 5 carbon atoms and n is an integer of 1 to 3.]SELECTED DRAWING: None

Description

[Technology Field]

[0001] The present invention relates to an antifouling coating composition, an antifouling coating film, a substrate with an antifouling coating film, and a method for producing a substrate with an antifouling coating film. [Background technology]

[0002] Surfaces of substrates exposed to water (oceans, rivers, lakes, etc.) for extended periods in natural environments (ships, underwater structures, fishing nets, seawater supply and drainage pipes in factories, etc.) are prone to the attachment of a wide variety of aquatic organisms. When aquatic organisms attach to the surface of a substrate, they can impair its appearance and cause various problems. For example, if the substrate is a ship, the increased resistance due to water flow can lead to a decrease in ship speed and an increase in fuel consumption. If the substrate is an underwater structure, the anti-corrosion coating applied to the substrate surface may be damaged, resulting in a decrease in strength and function, and a significant shortening of its lifespan. If the substrate is a fishing net such as an aquaculture net or a fixed net, aquatic organisms can clog the mesh, causing serious problems such as oxygen deprivation and death of farmed and caught organisms. When aquatic organisms attach to and proliferate in seawater supply and drainage pipes in factories and thermal and nuclear power plants, they can cause blockage of the pipes and a decrease in flow velocity.

[0003] To prevent the attachment of aquatic organisms that cause such problems, it is common practice to apply an antifouling coating to the surface of the substrate to form an antifouling film. Among these antifouling coatings, hydrolyzable antifouling coatings are widely used due to their advantages, such as exhibiting excellent antifouling performance, and the development of antifouling coatings containing silyl ester polymers has been progressing as one example.

[0004] Patent Document 1 describes an antifouling paint composition in which a copolymer containing structural units derived from styrene and structural units derived from glycidyl (meth)acrylate is incorporated into an antifouling paint containing a silyl ester polymer.

[0005] Patent Document 2 describes an antifouling coating composition that forms a self-polishing, antifouling coating by mixing an organosilyl copolymer with a (meth)acrylate polymer that is immiscible and phase-separable with respect to this copolymer.

[0006] Patent Document 3 describes an antifouling coating composition comprising a polymeric plasticizer consisting of an ethylenically unsaturated carboxylic acid ester polymer having a glass transition temperature of -20°C or lower and a number average molecular weight of 500 to 20000, and a triorganosilyl (meth)acrylate copolymer. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] International Publication No. 2014 / 175246 [Patent Document 2] Special Publication No. 2006-503115 [Patent Document 3] International Publication No. 2008 / 105122 [Overview of the project] [Problems that the invention aims to solve]

[0008] While coatings containing silyl ester polymers dissolve at a steady rate in seawater for a certain period from the initial immersion, over time, hydrolysis progresses within the coating, leading to a decrease in water resistance and problems such as cracking and peeling. To address this problem, blending acrylic copolymers with silyl ester polymers improves the crack resistance of the coating, but often reduces its antifouling properties. Although these problems have been examined in Patent Documents 1 to 3, there was still room for further improvement in achieving both long-term antifouling properties and water resistance (crack resistance) of the coating.

[0009] The object of the present invention is to provide an antifouling coating composition that can form an antifouling coating film that achieves both long-term antifouling properties and crack resistance of the coating film in seawater and freshwater. [Means for solving the problem]

[0010] The present inventors have diligently conducted research to solve the above problems and have found that the antifouling coating composition described below can solve the above problems. That is, the present invention relates to the following [1] to

[14] .

[0011] [1] An antifouling paint composition comprising a silyl ester polymer (A) and a copolymer (B) having a structural unit (b-1) derived from styrene and a structural unit (b-2) derived from a polymerizable monomer (b2) represented by formula (b2). Formula (b2): CH2=CH-COO-(R b1 -O) n -R b2 [In formula (b2), R b1 R is an alkanediyl group having 1 to 5 carbon atoms. b2 [where n is an alkyl group having 1 to 5 carbon atoms, and n is an integer from 1 to 3.]

[0012] [2] The antifouling paint composition according to [1], wherein the proportion of the structural unit (b-1) in the copolymer (B) is 30 to 80% by mass. [3] The antifouling coating composition according to [1] or [2], wherein the proportion of the structural unit (b-2) in the copolymer (B) is 15 to 45% by mass.

[0013] [4] The antifouling coating composition according to any one of [1] to [3], wherein the polymerizable monomer (b2) represented by formula (b2) is an alkoxyalkyl acrylate. [5] The antifouling paint composition according to [4], wherein the polymerizable monomer (b2) represented by formula (b2) is 2-methoxyethyl acrylate.

[0014] [6] The antifouling paint composition according to any one of [1] to [5], wherein the silyl ester polymer (A) has structural units derived from triisopropylsilyl methacrylate. [7] The antifouling coating composition according to any one of [1] to [6], wherein the mass ratio (A:B) of the silyl ester polymer (A) to the copolymer (B) is 90:10 to 30:70.

[0015] [8] The antifouling paint composition according to any one of [1] to [7], further containing a monocarboxylic acid compound (C). [9] The antifouling paint composition according to any one of [1] to [8], further containing copper and / or a copper compound (D).

[0016]

[10] The antifouling paint composition according to any one of [1] to [9], further containing an organic antifouling agent (E).

[11] An antifouling paint film formed from the antifouling paint composition according to any one of [1] to

[10] .

[0017]

[12] A substrate with an antifouling paint film, having a substrate and the antifouling paint film according to

[11] provided on the surface of the substrate.

[13] The substrate with an antifouling paint film according to

[12] , wherein the substrate is at least one selected from ships, underwater structures, fishing materials, and water supply and drainage pipes.

[0018]

[14] A method for manufacturing a substrate with an antifouling paint film, comprising a step of applying or impregnating the substrate with the antifouling paint composition according to any one of [1] to

[10] . [Effect of the Invention]

[0019] According to the present invention, it is possible to provide an antifouling paint composition capable of forming an antifouling paint film that can achieve both long-term antifouling property and crack resistance of the paint film in seawater and fresh water. [Embodiments for Carrying Out the Invention]

[0020] Hereinafter, embodiments of the present invention will be described in detail. Each component described in this specification can be used alone or in combination of two or more. "Polymer" is used in the sense of including homopolymers and copolymers. "(Meth)acrylate" is a term that collectively refers to acrylate and methacrylate. The same applies to examples in (meth)acrylic acid and the like.

[0021] The "structural unit derived from XX" means XX is A 1 A 2 C=CA 3 A 4 (C=C is a polymerizable carbon-carbon double bond, and A 1 ~A 4 are each an atom or group bonded to a carbon atom), if represented as, for example, it is a structural unit represented by the following formula.

[0022]

Chemical Formula 1

[0023] [Antifouling coating composition] The antifouling paint composition of this embodiment (hereinafter also referred to as "composition (I)") contains a silyl ester polymer (A), a structural unit (b-1) derived from styrene, and a copolymer (B) having a structural unit (b-2) derived from a polymerizable monomer (b2) represented by the following formula (b2).

[0024] <Silyl ester polymer (A)>[ The silyl ester polymer (A) (hereinafter also referred to as "polymer (A)") is a polymer having a structural unit derived from a silyl ester monomer. Polymer (A) preferably has a structural unit (a-1) derived from a polymerizable monomer (a1) represented by formula (a1).

[0025]

Chemical Formula 2

[0026] R 1 is a hydrogen atom or a methyl group, preferably a methyl group. R 2 ~R 6These are monovalent organic groups having 1 to 20 carbon atoms, each of which may independently have heteroatoms. Examples of these organic groups include linear or branched alkyl groups, cycloalkyl groups, and aryl groups, in which heteroatoms such as oxygen atoms may be interposed between the carbon atoms. From the viewpoint of easily obtaining an antifouling coating film that has a good balance of moderate hydrolysis resistance, long-term antifouling properties, and water resistance (crack resistance), it is preferably at least one selected from linear or branched alkyl groups having 1 to 8 carbon atoms and phenyl groups, and more preferably a branched alkyl group.

[0027] Examples of linear or branched alkyl groups include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, t-butyl, pentyl, hexyl, and 2-ethylhexyl groups, with isopropyl being preferred.

[0028] n is an integer greater than or equal to 0, preferably 0. The upper limit of n may be, for example, 50. X is a hydrogen atom or R 7 It is a group represented by -OC(=O)-, preferably a hydrogen atom. 7 is a monovalent organic group having 1 to 20 carbon atoms, which may have a hydrogen atom or a heteroatom, or R 8 R 9 R 10 This is a silyl group represented by Si-. 8 , R 9 and R 10 These are monovalent organic groups having 1 to 20 carbon atoms, each of which may independently contain heteroatoms. The specific examples of monovalent organic groups having 1 to 20 carbon atoms that may contain heteroatoms are those mentioned above.

[0029] Preferred polymerizable monomers (a1) include trialkylsilyl (meth)acrylate, alkyldiarylsilyl (meth)acrylate, and aryldialkylsilyl (meth)acrylate, with trialkylsilyl (meth)acrylate being more preferred. Examples of trialkylsilyl (meth)acrylates include trimethylsilyl (meth)acrylate, triethylsilyl (meth)acrylate, tripropylsilyl (meth)acrylate, triisopropylsilyl (meth)acrylate, tributylsilyl (meth)acrylate, triisobutylsilyl (meth)acrylate, tri-sec-butylsilyl (meth)acrylate, tri-2-ethylhexylsilyl (meth)acrylate, and butyldiisopropylsilyl (meth)acrylate. In addition, polymerizable monomers (a1) such as 1-(meth)acryloyloxynonamethyltetrasiloxane, in which n is 2 or more, can also be used. Among these, trialkylsilyl (meth)acrylate with a branched alkyl group is preferred, triisopropylsilyl (meth)acrylate is more preferred, and triisopropylsilyl methacrylate is particularly preferred, from the viewpoint that it is possible to easily obtain an antifouling coating film that has a good balance of moderate hydrolysis properties, long-term antifouling properties and water resistance (crack resistance).

[0030] The structural unit (a-1) may be of one type or of two or more types. Polymer (A) may further have structural units (a-2) derived from other ethylenically unsaturated monomers (hereinafter also referred to as "monomer (a2)").

[0031] For example, the monomer (a2) is: (meth)acrylic acid; (Meth)acrylic acid esters, specifically alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 3,5,5-trimethylhexyl (meth)acrylate, lauryl (meth)acrylate, cetyl (meth)acrylate, stearyl (meth)acrylate, etc.; Cyclohexyl (meth)acrylate and other alicyclic (meth)acrylates; Aromatic ring-containing (meth)acrylates such as phenyl (meth)acrylate and benzyl (meth)acrylate; Hydroxyalkyl (meth)acrylates such as hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate; Alkoxyalkyl (meth)acrylates or allyloxyalkyl (meth)acrylates such as methoxymethyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, ethoxymethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 4-methoxybutyl (meth)acrylate, methoxypropyl (meth)acrylate, ethoxypropyl (meth)acrylate, propoxyethyl (meth)acrylate, 2-butoxyethyl (meth)acrylate, isobutoxyethyl (meth)acrylate, phenoxyethyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate; Glycol-based (meth)acrylates such as ethoxy-diethylene glycol (meth)acrylate, methoxy-triethylene glycol (meth)acrylate, and methoxy-dipropylene glycol (meth)acrylate; Vinyl monomers, specifically vinyl acetate, isobutyl vinyl ether, styrene, vinyltoluene, (meth)acrylonitrile, vinyl propionate, vinyl benzoate; Metal ester group-containing (meth)acrylates, specifically zinc (meth)acrylate, zinc di(meth)acrylate, copper (meth)acrylate, copper di(meth)acrylate These are some examples.

[0032] The structural unit (a-2) may be of one type or of two or more types. The proportion of structural unit (a-1) in polymer (A) is preferably 35% by mass or more, more preferably 40% by mass or more, even more preferably 45% by mass or more, preferably 80% by mass or less, more preferably 75% by mass or less, and even more preferably 70% by mass or less.

[0033] The proportion of structural unit (a-2) in polymer (A) is preferably 20% by mass or more, more preferably 25% by mass or more, even more preferably 30% by mass or more, preferably 65% ​​by mass or less, more preferably 60% by mass or less, and even more preferably 55% by mass or less.

[0034] When the proportion of each structural unit is within the above range, the antifouling coating formed from composition (I) tends to have moderate hydrolytic properties and excellent antifouling properties over the long term. The proportion of each structural unit can be determined by NMR (nuclear magnetic resonance spectroscopy), Pyro-GC / MS (thermolysis gas chromatography-mass spectrometry), etc.

[0035] The weight-average molecular weight (Mw) of polymer (A) is preferably 3,000 or more, more preferably 10,000 or more, preferably 70,000 or less, and more preferably 50,000 or less, from the viewpoint of improving the crack resistance of the antifouling coating film formed from composition (I). Mw can be determined by gel permeation chromatography (GPC) measurement under the conditions used in the examples described later, or by an equivalent method. Polymer (A) can be of one type or two or more types.

[0036] <Copolymer (B)>[ The copolymer (B) has a structural unit (b-1) derived from styrene and a structural unit (b-2) derived from a polymerizable monomer (b2) represented by formula (b2). Formula (b2): CH2=CH-COO-(R b1 -O) n -R b2 In formula (b2), R b1 R is an alkanediyl group having 1 to 5 carbon atoms, preferably 1 to 3 carbon atoms, b2 n is an alkyl group having 1 to 5 carbon atoms, preferably 1 to 3 carbon atoms, and n is an integer from 1 to 3, preferably 1.

[0037] Examples of alkanediyl groups include methanediyl group, ethane-1,2-diyl group, propane-1,3-diyl group, propane-1,2-diyl group, and butane-1,4-diyl group. Examples of alkyl groups include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, t-butyl group, and pentyl group.

[0038] Examples of polymerizable monomers (b2) include: Alkoxyalkyl acrylates such as methoxymethyl acrylate, 2-methoxyethyl acrylate, ethoxymethyl acrylate, 2-ethoxyethyl acrylate, 4-methoxybutyl acrylate, methoxypropyl acrylate, ethoxypropyl acrylate, propoxyethyl acrylate, 2-butoxyethyl acrylate, and isobutoxyethyl acrylate; Glycol-based acrylates such as ethoxy-diethylene glycol acrylate, methoxy-triethylene glycol acrylate, and methoxy-dipropylene glycol acrylate; These are some examples.

[0039] Among these, alkoxyalkyl acrylates are preferred, and 2-methoxyethyl acrylate (MEA) is particularly preferred. The structural unit (b-2) may be of one type or of two or more types.

[0040] Structural unit (b-1) has a hydrophobic functional group, a phenyl group, and contributes to improving the water resistance (crack resistance) of the antifouling coating film formed from composition (I), as well as improving the coating hardness, impact resistance, and abrasiveness. The reason for the improved abrasiveness is not clear, but it is presumed that structural unit (b-1) improves the coating hardness of the formed antifouling coating film, and thus exhibits physical abrasiveness against external forces such as frictional resistance in water. Structural unit (b-2) contributes to improving the hydrophilicity of the antifouling coating.

[0041] Copolymer (B) typically does not contain structural units derived from silyl ester monomers. When an acrylic copolymer without hydrolyzable groups is blended with a silyl ester polymer, the crack resistance of the coating film generally improves, while the antifouling properties tend to decrease. This is thought to be because the silyl ester polymer undergoes a hydrolysis reaction in water, where its side chains become water-soluble polymers that leach out. The presence of the acrylic copolymer without hydrolyzable groups in the coating film inhibits this hydrolysis reaction. Therefore, it was thought that using a copolymer of styrene and a hydrophilic monomer as the acrylic copolymer would provide a good balance between hydrophobicity and hydrophilicity in the antifouling coating film, thus achieving both long-term antifouling properties and crack resistance. However, the inventors' research has shown that such an effect is not always achieved depending on the type of hydrophilic monomer used.

[0042] Further investigations by the inventors revealed that by incorporating a copolymer of styrene and the aforementioned polymerizable monomer (b2), particularly MEA, into a silyl ester polymer, a particularly good balance between hydrophobicity and hydrophilicity of the antifouling coating film is achieved, enabling both long-term antifouling properties and crack resistance.

[0043] The proportion of structural units (b-1) in copolymer (B) is preferably 30% by mass or more, more preferably 40% by mass or more, even more preferably 45% by mass or more, preferably 80% by mass or less, and more preferably 75% by mass or less. When the proportion of structural units (b-1) is above the lower limit, the water resistance (crack resistance) of the antifouling coating film is high, which is preferable. When the proportion of structural units (b-1) is below the upper limit, the hydrophobicity of the antifouling coating film is not too high and does not hinder the hydrolysis of polymer (A), resulting in excellent antifouling properties.

[0044] The proportion of structural units (b-2) in copolymer (B) is preferably 15% by mass or more, more preferably 20% by mass or more, preferably 45% by mass or less, and more preferably 40% by mass or less. When the proportion of structural units (b-2) is above the lower limit, the antifouling properties of the antifouling coating film are high, which is preferable. When the proportion of structural units (b-2) is below the upper limit, the hydrophilicity of the antifouling coating film is not too high, and the antifouling agent does not dissolve excessively into water, which is preferable because it provides high antifouling properties not only in the short term (e.g., 12 months) but also in the long term (e.g., 36 months).

[0045] In recent years, the service life of antifouling coatings can extend to long periods, such as 90 months. By using a copolymer (B) having structural units (b-1) and (b-2), it is possible to achieve both long-term antifouling properties and crack resistance in the antifouling coating. In particular, by keeping the proportions of structural units (b-1) and (b-2) within the above-mentioned ranges, the decrease in crack resistance of the antifouling coating in regions with a high proportion of structural units (b-2) can be compensated for by the hydrophobicity of structural unit (b-1), thus achieving both long-term antifouling properties and crack resistance.

[0046] In one embodiment of copolymer (B), when the proportion of structural units (b-2) is 15 to 45% by mass, the antifouling properties are further improved compared to when the proportion of structural units (b-2) is less than 15% by mass, and the long-term antifouling properties are further improved compared to when the proportion of structural units (b-2) is greater than 45% by mass. In one embodiment of copolymer (B), when the proportion of structural units (b-1) is 30 to 80% by mass, the crack resistance is further improved compared to when the proportion of structural units (b-1) is less than 30% by mass, and the antifouling properties are further improved compared to when the proportion of structural units (b-1) is greater than 80% by mass.

[0047] The proportion of each structural unit can be determined using the same method as for polymer (A). Copolymer (B) may further have structural units (b-3) derived from other ethylenically unsaturated monomers (hereinafter also referred to as "monomer (b3)").

[0048] For example, the monomer (b3) is: (meth)acrylic acid; (Meth)acrylic acid esters (excluding polymerizable monomers (b2)), specifically alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 3,5,5-trimethylhexyl (meth)acrylate, lauryl (meth)acrylate, cetyl (meth)acrylate, and stearyl (meth)acrylate; Cyclohexyl (meth)acrylate and other alicyclic (meth)acrylates; Aromatic ring-containing (meth)acrylates such as phenyl (meth)acrylate and benzyl (meth)acrylate; Hydroxyalkyl (meth)acrylates such as hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate; Alkoxyalkyl methacrylates or aryloxyalkyl (meth)acrylates such as methoxymethyl methacrylate, 2-methoxyethyl methacrylate, ethoxymethyl methacrylate, 2-ethoxyethyl methacrylate, 4-methoxybutyl methacrylate, methoxypropyl methacrylate, ethoxypropyl methacrylate, propoxyethyl methacrylate, 2-butoxyethyl methacrylate, isobutoxyethyl methacrylate, phenoxyethyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate; Glycol-based methacrylates such as ethoxy-diethylene glycol methacrylate, methoxy-triethylene glycol methacrylate, and methoxy-dipropylene glycol methacrylate; Epoxy group-containing (meth)acrylates such as glycidyl (meth)acrylate; Polyfunctional (meth)acrylates, specifically tetraethylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, di(trimethylolpropane)tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate; Vinyl monomers, specifically vinyl acetate, isobutyl vinyl ether, vinyltoluene, (meth)acrylonitrile, vinyl propionate, vinyl benzoate These are some examples.

[0049] Among these, (meth)acrylic acid esters are preferred, alkyl (meth)acrylates are more preferred, and methyl (meth)acrylates are even more preferred. The structural unit (b-3) may be of one type or two or more types.

[0050] The proportion of structural unit (b-3) in copolymer (B) is preferably 55% by mass or less, more preferably 45% by mass or less, and even more preferably 40% by mass or less, from the viewpoint of not inhibiting the above-mentioned effects of structural unit (b-1) and structural unit (b-2).

[0051] The weight-average molecular weight (Mw) of copolymer (B) is preferably 3,000 or more, more preferably 5,000 or more, even more preferably 7,000 or more, preferably 35,000 or less, more preferably 30,000 or less, and even more preferably 25,000 or less, from the viewpoint of improving the crack resistance of the antifouling coating film formed from composition (I). Mw can be determined by gel permeation chromatography (GPC) measurement under the conditions adopted in the examples described later, or by an equivalent method.

[0052] Copolymer (B) can be one or more types. The content ratio of polymer (A) to copolymer (B) in composition (I) is preferably as follows: The mass ratio (A:B) of polymer (A) to copolymer (B) is preferably 90:10 to 30:70, more preferably 80:20 to 40:60, and even more preferably 75:25 to 45:55. This configuration is preferable because it further improves the long-term antifouling properties and crack resistance of the antifouling coating.

[0053] The total content of polymer (A) and copolymer (B) is preferably 5% by mass or more, more preferably 10% by mass or more, preferably 30% by mass or less, and more preferably 20% by mass or less, based on 100% by mass of the total solid content of composition (I). When the total content is within this range, an antifouling coating with excellent crack resistance can be easily obtained.

[0054] Furthermore, from the viewpoint of producing a composition with excellent paintability, the solid content in composition (I) is preferably 50% by mass or more, more preferably 65% ​​by mass or more, preferably 90% by mass or less, and more preferably 85% by mass or less.

[0055] In this specification, the solid content of composition (I) and its content are the heating residue (non-volatile content) and its content obtained by the following method or an equivalent method. Composition (I) was weighed into a metal test dish of known mass, spread on the bottom surface, heated in a constant temperature bath maintained at 105-110°C for 3 hours, removed, cooled to room temperature (e.g., 23°C), and then weighed again to determine the amount remaining in the metal test dish. The solid content (mass %) was calculated by the following formula. Solid content (mass %) = Amount remaining in the metal test dish (g) × 100 / Mass of composition (I) weighed out (g) The same applies to the solid content and percentage of each component.

[0056] <Method for producing polymer>[ The method for producing polymer (A) and copolymer (B) is not particularly limited, but examples include solution polymerization, suspension polymerization, and pressure polymerization. Solution polymerization carried out under normal pressure using a general organic solvent is preferred due to its high versatility. The solution polymerization can be carried out by the following procedure.

[0057] A reaction vessel equipped with a stirrer, condenser, thermometer, dropping device, nitrogen inlet tube, and heating / cooling jacket is filled with a solvent and heated and stirred under a nitrogen stream at a temperature of approximately 60 to 200°C. While maintaining the same temperature, the monomers, polymerization initiator, and optionally a mixture of solvent and chain transfer agent are dropped from the dropping device, preferably in the proportions of the structural units described above, to carry out a polymerization reaction and obtain polymer (A) or copolymer (B).

[0058] There are no particular restrictions on the polymerization initiator, and various radical polymerization initiators can be used. Specifically, examples include 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 4,4'-azobis-4-cyanovaleric acid, benzoyl peroxide, hydrogen peroxide, cumene hydroperoxide, tert-butyl hydroperoxide, tert-butyl peroxyoctoate, tert-butyl peroxybenzoate, potassium persulfate, sodium persulfate, etc. These radical polymerization initiators may be added to the reaction system only at the start of the reaction, or they may be added to the reaction system both at the start of the reaction and during the reaction.

[0059] The amount of polymerization initiator used in the production of polymer (A) or copolymer (B) is preferably 0.1 to 20 parts by mass, and more preferably 0.5 to 5 parts by mass, per 100 parts by mass of the total amount of each monomer (reaction material).

[0060] Examples of solvents that can be used in the production of polymer (A) or copolymer (B) include organic solvents and water. Examples of organic solvents include aromatic hydrocarbon solvents such as toluene, xylene, ethylbenzene, mesitylene, and coal tar naphtha; alcohol solvents such as ethanol, propanol, isopropyl alcohol, butanol, and isobutanol; ether solvents such as propylene glycol monomethyl ether and dipropylene glycol monomethyl ether; ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, methyl amyl ketone, and cyclohexanone; and ester solvents such as ethyl acetate, butyl acetate, and propylene glycol monomethyl ether acetate.

[0061] There are no particular restrictions on the chain transfer agent, and examples include α-methylstyrene dimer, thioglycolic acid, diterpenes, terpinolene, γ-terpinene; mercaptans such as tert-dodecyl mercaptan and n-dodecyl mercaptan; halides such as carbon tetrachloride, methylene chloride, bromoform, and bromotrichloroethane; and secondary alcohols such as isopropanol and glycerin.

[0062] When a chain transfer agent is used in the production of a silyl ester polymer (A), the amount used is preferably 0.1 to 5 parts by mass per 100 parts by mass of the total amount of each monomer (reaction material) mentioned above.

[0063] <Other components>[ Composition (I) may further contain one or more of the following as other components: monocarboxylic acid compounds (C), copper and / or copper compounds (D), organic antifouling agents (E), colorants, extender pigments, thixotropes, dehydrating agents, plasticizers, resins other than polymers (A) and copolymers (B), and solvents. Each of the components described below can be used individually or in combination of two or more.

[0064] ≪Monocarboxylic acid compound (C)≫[ Composition (I) preferably contains a monocarboxylic acid compound (C) from the viewpoint of not only improving stain resistance but also being able to adjust the rate of wear of the coating film.

[0065] Examples of monocarboxylic acid compounds (C) include aliphatic or alicyclic monocarboxylic acids, their monocarboxylic acid derivatives, or their metal salts. Examples of monocarboxylic acid derivatives include esters and amides of monocarboxylic acids. Examples of metal salts include zinc salts, copper salts, aluminum salts, magnesium salts, calcium salts, and barium salts. Specific examples of monocarboxylic acids include rosins, naphthenic acid, cycloalkenyl carboxylic acids, bicycloalkenyl carboxylic acids, trimethylisobutenylcyclohexene carboxylic acid, isononanoic acid, neodecanoic acid, versatic acid, stearic acid, hydroxystearic acid, palmitic acid, oleic acid, linoleic acid, linolenic acid, pimaric acid, abietic acid, and neoabietic acid. Examples of rosins include gum rosin, wood rosin, tall oil rosin, etc.; hydrogenated rosin, disproportionated rosin, rosin metal salts and other rosin derivatives, and pine tar. Preferred monocarboxylic acid compounds (C) include rosin, rosin derivatives, naphthenic acid, versatic acid, trimethylisobutenylcyclohexenecarboxylic acid, and metal salts thereof.

[0066] The mass ratio of monocarboxylic acid compound (C) in composition (I) (total mass of polymer (A) and copolymer (B): mass of monocarboxylic acid compound (C)) is preferably 95:5 to 40:60, more preferably 90:10 to 50:50.

[0067] ≪Copper and / or copper compound (D)≫[ Composition (I) preferably contains copper and / or a copper compound (D) as an antifouling agent, from the viewpoint of further improving its antifouling properties against aquatic organisms of animal species. Examples of copper include copper powder. Examples of copper compounds include cuprous oxide, copper thiocyanate, and cupronickel, with cuprous oxide and copper thiocyanate being preferred. Note that copper pyrithione is not a copper compound but is classified as an organic antifouling agent (E) below.

[0068] The content of copper and / or copper compounds (D) is preferably 0.1 to 70% by mass, more preferably 1 to 60% by mass, based on 100% by mass of the total solid content of composition (I).

[0069] ≪Organic antifouling agent (E)≫[ Composition (I) preferably contains an organic antifouling agent (E) as an antifouling agent. The organic antifouling agent (E) is a component that further improves the antifouling properties of the antifouling coating.

[0070] Examples of organic antifouling agents (E) include metal pyrithiones such as copper pyrithione and zinc pyrithione, 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one, 4-bromo-2-(4-chlorophenyl)-5-(trifluoromethyl)-1H-pyrrole-3-carbonitrile, pyridinetriphenylborane, 4-isopropylpyridinediphenylmethylborane, N,N-dimethyl-N'-(3,4-dichlorophenyl)urea, N-(2,4,6-trichlorophenyl)maleimide, 2-methylthio-4-tert-butylamino-6-cyclopropylamino-1,3,5-triazine, and medetomidine((+ / -)-4-[1-(2,3-dimethylphenyl)ethyl] Examples include -1H-imidazole, 2,4,5,6-tetrachloroisophthalonitrile, bisdimethyldithiocarbamoylzinc ethylenebisdithiocarbamate, chloromethyl-n-octyl disulfide, N',N'-dimethyl-N-phenyl-(N-fluorodichloromethylthio)sulfamide, N',N'-dimethyl-N-tolyl-(N-fluorodichloromethylthio)sulfamide, tetraalkylthiuram disulfide, zinc dimethyldithiocarbamate, zinc ethylenebisdithiocarbamate, 2,3-dichloro-N-(2',6'-diethylphenyl)maleimide, and 2,3-dichloro-N-(2'-ethyl-6'-methylphenyl)maleimide. Among these, metal pyrithiones such as copper pyrithione and zinc pyrithione, medetomidine, 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one, 4-bromo-2-(4-chlorophenyl)-5-(trifluoromethyl)-1H-pyrrole-3-carbonitrile, and bisdimethyldithiocarbamoylzincethylenebisdithiocarbamate are preferred, copper pyrithione, medetomidine, and 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one are more preferred, and copper pyrithione and medetomidine are even more preferred.

[0071] The content of the organic antifouling agent (E) is preferably 0.05 to 20% by mass, more preferably 0.1 to 10% by mass, based on 100% by mass of the total solid content of composition (I).

[0072] ≪Colorant≫[ As colorants, various conventionally known organic and inorganic pigments and dyes can be used. Examples of organic pigments include naphthol red and phthalocyanine blue. Examples of inorganic pigments include carbon black, iron oxide, barite powder, titanium white (titanium dioxide), and yellow iron oxide. It is preferable that composition (I) contains a colorant in that the hue of the antifouling coating obtained from the composition can be arbitrarily adjusted. The coloring agent content is preferably 0.01 to 50% by mass, more preferably 0.01 to 30% by mass, based on 100% by mass of the total solid content of composition (I).

[0073] ≪Extender pigment≫[ Examples of extender pigments include zinc oxide, talc, silica, mica, clay, potassium feldspar, calcium carbonate, kaolin, alumina white, white carbon, aluminum hydroxide, magnesium carbonate, barium carbonate, barium sulfate, and zinc sulfide. Among these, zinc oxide, talc, silica, mica, clay, calcium carbonate, kaolin, barium sulfate, and potassium feldspar are preferred.

[0074] Composition (I) preferably contains an extender pigment, from the viewpoint of improving the physical properties of the resulting antifouling coating, such as crack resistance. The extender pigment content is preferably 0.1 to 50% by mass, more preferably 1 to 40% by mass, based on 100% by mass of the total solid content of composition (I).

[0075] ≪Thixotropic agent≫[ Switogenic agents are components that contribute to preventing paint from sagging and settling. Examples of anti-sagging agents (anti-sagging agents, anti-settlement agents) include: organic bentonite, salts selected from the group consisting of amine salts, stearate salts, lecithin salts, and alkyl sulfonates of Al, Ca, or Zn; waxes selected from the group consisting of polyethylene wax, oxidized polyethylene wax, amide wax, hydrogenated castor oil wax, and polyamide wax; and synthetic fine silica.

[0076] The thixotrope is used to prevent the precipitation of solid materials such as copper and / or copper compounds (D), organic antifouling agents (E), colorants, extender pigments, and dehydrating agents during storage of the antifouling paint composition, and to improve the workability of the paint during application. The content of the thixotrope is preferably 0.1 to 20% by mass, more preferably 0.1 to 10% by mass, based on 100% by mass of the total solid content of composition (I).

[0077] ≪Dehydrating agent≫[ Examples of dehydrating agents include inorganic and organic dehydrating agents. For example, inorganic dehydrating agents include synthetic zeolites and anhydrous gypsum / hemihydrate gypsum, while organic dehydrating agents include alkoxysilanes such as tetramethoxysilane, tetraethoxysilane, tetrabutoxysilane, tetraphenoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, and trimethylethoxysilane, or their condensates, polyalkoxysilanes, and alkyl orthoformate esters such as methyl orthoformate and ethyl orthoformate. Dehydrating agents are used to prevent gelation due to the decomposition of hydrolyzable resins caused by moisture generated during the manufacture and / or storage of antifouling paint compositions. The amount of dehydrating agent is preferably 0.01 to 10% by mass, more preferably 0.1 to 5% by mass, based on 100% by mass of the total solid content of composition (I).

[0078] ≪Plasticizer≫[ Examples of plasticizers include n-paraffin, chlorinated paraffin, petroleum resin, ketone resin, tricresyl phosphate, polyvinyl ethyl ether, and dialkyl phthalate, with chlorinated paraffin, petroleum resin, and ketone resin being preferred among these. The inclusion of a plasticizer in composition (I) is preferable because it further improves the crack resistance and water resistance of the antifouling coating obtained from the composition.

[0079] Chlorinated paraffins may have either linear or branched molecular structures, and may be liquid or solid (powder) at room temperature. Furthermore, the average number of carbon atoms in chlorinated paraffin is preferably 8 to 30, more preferably 10 to 26, per molecule. Antifouling coating compositions containing such chlorinated paraffin can form antifouling coatings with fewer cracks and peeling. It should be noted that an average number of carbon atoms of 8 or more provides a high crack suppression effect, while an average number of carbon atoms of 30 or less is preferable because it does not suppress antifouling properties.

[0080] Furthermore, the viscosity of the chlorinated paraffin (in poise, measured at 25°C) is preferably 1 or higher, more preferably 1.2 or higher, and the specific gravity (at 25°C) is preferably 1.05 to 1.80 g / cm³. 3 More preferably 1.10 to 1.70 g / cm³ 3 That is the case.

[0081] Examples of petroleum resins include C5-based, C9-based, styrene-based, and dicyclopentadiene-based resins, as well as their hydrogenated versions. The plasticizer content is preferably 0.01 to 10% by mass, more preferably 0.1 to 5% by mass, based on 100% by mass of the total solid content of composition (I).

[0082] ≪Resins other than polymer (A) and copolymer (B)≫[ Composition (I) may contain resins other than the polymer (A) and copolymer (B) described above. Examples of such resins include water-insoluble or poorly water-soluble resins such as polyester resins, unsaturated polyester resins, fluororesins, polybutene resins, polyurethane resins, epoxy resins, polyamide resins, vinyl resins (vinyl chloride copolymers, ethylene-vinyl acetate copolymers, etc.), chlorinated olefin resins, styrene-butadiene copolymer resins, alkyd resins, coumarone resins, terpene phenol resins, silicone rubber, and chlorinated rubber. The content of the above resins is, for example, 0.01 to 100 parts by mass per 100 parts by mass of the total of polymer (A) and copolymer (B).

[0083] ≪Solvent≫[ Composition (I) may contain solvents such as water or organic solvents as needed to improve the dispersibility of each component or to adjust the viscosity of the composition. The solvent may be the solvent used when preparing polymer (A) or copolymer (B), or it may be a solvent added separately when mixing polymer (A) and copolymer (B) with other components as needed to prepare an antifouling coating composition. Organic solvents are preferred as the solvent. Examples of organic solvents include those described in the section on <Method for producing polymers>.

[0084] If composition (I) contains a solvent, the preferred amount is determined by the desired viscosity according to the application method of the paint composition. The solvent content in composition (I) is preferably 5 to 50% by mass, more preferably 10 to 40% by mass. If the solvent content is too high, problems such as a decrease in anti-sagging properties may occur.

[0085] <Method for producing antifouling coating composition>[ Composition (I) can be manufactured using known methods, except that it uses polymer (A) and copolymer (B). For example, polymer (A), copolymer (B), and other components as needed may be added to a stirring vessel all at once or in any order, and the components may be mixed using known stirring and mixing means, and then dispersed or dissolved in a solvent.

[0086] Examples of stirring and mixing methods include using a paint shaker, high-speed disperser, sand grind mill, basket mill, ball mill, three-roll mill, loss mixer, planetary mixer, and multi-purpose Shinagawa agitator.

[0087] [Use of antifouling coating composition][ The antifouling coating of this embodiment (hereinafter also referred to as "antifouling coating (J)") is formed from composition (I). The substrate with the antifouling coating of this embodiment (hereinafter also referred to as "antifouling substrate (K)") comprises a substrate and an antifouling coating (J) provided on the surface of the substrate.

[0088] A method for producing an antifouling substrate (K) comprises the steps of applying or impregnating a substrate (target object, object to be coated) with composition (I), and if composition (I) contains a solvent, further comprising the step of drying the coated or impregnated body obtained by applying or impregnating the substrate.

[0089] For application, known methods such as air spray, airless spray, brush, and roller can be used. The composition (I) applied or impregnated by the method described above can be dried, for example, by leaving it at -5 to 30°C for about 1 to 10 days, more preferably about 1 to 7 days, to obtain an antifouling coating (J). The drying of composition (I) may also be carried out under heating with a fan.

[0090] Alternatively, the antifouling substrate (K) can be manufactured by forming an antifouling coating (J) from composition (I) on the surface of a temporary substrate, peeling off this antifouling coating (J) from the temporary substrate, and attaching it to the substrate to be protected from fouling. In this case, the antifouling coating (J) may be attached to the substrate via an adhesive layer.

[0091] The substrate may have a primer-treated surface, and may have a layer formed from various resin-based coatings such as epoxy resin coatings, vinyl resin coatings, acrylic resin coatings, and urethane resin coatings on its surface. In this case, the surface of the substrate on which the antifouling coating (J) is provided refers to the surface after primer treatment or the surface of the layer formed from the above coatings.

[0092] While there are no particular limitations on the base material, composition (I) is preferably used in a wide range of industrial fields such as ships, fisheries, and underwater structures to provide long-term antifouling protection for the base material. For this reason, suitable base materials include, for example, ships (e.g., large steel vessels such as container ships and tankers, fishing boats, FRP boats, wooden boats, yachts, etc., including both newly built and repaired vessels), underwater structures (e.g., oil pipelines, water intake pipes, circulating water pipes, water inlets and outlets for factories and thermal / nuclear power plants, submarine cables, seawater utilization equipment (seawater pumps, etc.), mega-floats, coastal roads, underwater tunnels, port facilities, and various underwater civil engineering structures in canals and waterways), fishing materials (e.g., ropes, fishing nets, fishing gear, floats, buoys), water inlets and outlets for seawater in factories and thermal / nuclear power plants, diver suits, goggles, oxygen tanks, swimwear, torpedoes, etc.). Among these, ships, underwater structures, fishing materials, and water supply and drainage pipes are preferred, ships and underwater structures are more preferred, and ships are particularly preferred.

[0093] When manufacturing the antifouling substrate (K), if the substrate is a fishing net or a steel plate, composition (I) may be applied directly to the surface of the substrate; if the substrate is a fishing net, composition (I) may be impregnated into its surface; if the substrate is a steel plate, a base material such as a rust inhibitor or primer may be applied to the surface of the substrate beforehand to form a base layer, and then composition (I) may be applied to the surface of the base layer. Furthermore, in the case of a steel plate with a deteriorated antifouling coating, an antifouling coating (J) may be further formed on the surface of a substrate on which an antifouling coating (J) or a conventional antifouling coating has been formed, for the purpose of repair.

[0094] The thickness of the antifouling coating (J) is not particularly limited, but is, for example, about 30 to 1000 μm. When forming the antifouling coating (J) by applying composition (I) to a substrate, the thickness of the antifouling coating (J) formed in a single coating is preferably 10 to 300 μm, more preferably 30 to 200 μm, and can be achieved by applying it one to multiple times.

[0095] Ships with an antifouling coating (J) can prevent a decrease in ship speed and an increase in fuel consumption because they can prevent the attachment of aquatic organisms. Underwater structures with an antifouling coating (J) can maintain their function for a long period of time because they can prevent the attachment of aquatic organisms over a long period of time. Fishing nets with an antifouling coating (J) can prevent clogging of the mesh because they can prevent the attachment of aquatic organisms. In addition, water supply and drainage pipes with an antifouling coating (J) on their inner surface can prevent clogging of the pipes and a decrease in flow velocity because they can prevent the attachment and reproduction of aquatic organisms. [Examples]

[0096] The present invention will be described in more detail below based on examples and comparative examples, but the present invention is not limited in any way to the following examples. In the following examples and comparative examples, "parts" refers to "parts by mass".

[0097] [Measurement conditions][ Gel permeation chromatography (GPC) was performed on the polymer, and the content of the heating residue was measured in the copolymer solution. The measurement conditions for each were as follows.

[0098] <GPC measurement conditions>[ Equipment: "HLC-8320GPC" (manufactured by Tosoh Corporation) Column: "TSKgel guardcolumn SuperMP(HZ)-M + TSKgel SuperMultiporeHZ-M + TSKgel SuperMultiporeHZ-M" (all manufactured by Tosoh Corporation) Eluent: Tetrahydrofuran (THF) Flow rate: 0.35ml / min Detector: RI Column constant temperature bath temperature: 40℃ Calibration curve: Standard polystyrene and styrene monomers Sample preparation method: The copolymer solution obtained in each production example was diluted with THF, and the filtrate obtained by filtering through a membrane filter was used as the GPC measurement sample.

[0099] <Measurement conditions for content of heat residue>[ The copolymer solution was weighed into a metal test dish of known mass, spread on the bottom surface, and heated in a constant temperature bath maintained at 105-110°C for 3 hours. After removing the dish and allowing it to cool to room temperature, the mass was weighed again to determine the remaining amount in the metal test dish. The solid content (mass %) was calculated using the following formula. Solid content (mass %) = Amount remaining in the metal test dish (g) × 100 / Mass of copolymer solution measured out (g)

[0100] [Production example of polymer][ [Production example 1] Production of solution of silyl ester polymer (A)[ 43 parts xylene and 10 parts triisopropylsilyl methacrylate were charged into a reaction vessel equipped with a stirrer, condenser, thermometer, nitrogen inlet tube, and dropper, and the mixture was heated and stirred under a nitrogen atmosphere until the liquid temperature reached 80°C. While maintaining these conditions, a mixture of monomers (50 parts triisopropylsilyl methacrylate, 25 parts 2-methoxyethyl methacrylate, 10 parts methyl methacrylate, and 5 parts butyl acrylate) and polymerization initiator (1.35 parts 2,2'-azobis (isobutyronitrile)) was added dropwise to the reaction vessel over 2 hours using the dropper. Then, heating and stirring were continued at the same temperature for 1 hour, and then at a liquid temperature of 88°C for 1 hour, after which the liquid temperature was raised to 95°C. While maintaining this temperature, 0.1 parts 2,2'-azobis (isobutyronitrile) were added at 30-minute intervals for a total of four times, and then the liquid temperature was raised to 105°C. After continuing heating and stirring at the same temperature for 30 minutes, 23.7 parts of xylene were added to the reaction vessel to obtain a solution of silyl ester copolymer (A-1) (polymer solution (A-1)). The weight-average molecular weight of silyl ester copolymer (A-1) was 28,649. The content of the heating residue in the above solution was 60.0% by mass.

[0101] [Production example 2] Production of solution of copolymer (B)[ 66.7 parts xylene were charged into a reaction vessel equipped with a stirrer, condenser, thermometer, nitrogen inlet tube, and dropping device, and the mixture was heated and stirred under a nitrogen atmosphere until the liquid temperature reached 110°C. While maintaining the same conditions, a mixture of monomers (70 parts styrene, 30 parts 2-methoxyethyl acrylate) and polymerization initiator (4 parts 2,2'-azobis(isobutyronitrile), 1 part tert-butyl peroxybenzoate) was added dropwise to the reaction vessel from the dropping device over 3 hours. Then, heating and stirring were continued at the same temperature for 1 hour, at 120°C for 1 hour, and at 130°C for 1 hour to obtain a copolymer solution (copolymer solution (B-1)).

[0102] The monomers were changed as shown in Table 1, and the same procedure as above was performed while appropriately adjusting the liquid temperature and the amount of polymerization initiator to obtain solutions of copolymer (B) (polymer solution (B-2) to copolymer solution (B-14)) and solutions of the comparison copolymer (cB) (polymer solution (cB-1) to copolymer solution (cB-7)).

[0103] The property values ​​are shown in Table 1. The values ​​for monomers indicate the amount (parts by mass) used. The content of the heating residue in all of the above solutions was approximately 60% by mass. St: Styrene MMA: Methyl methacrylate BA: n-butyl acrylate MEA: 2-Methoxyethyl acrylate MEMA: 2-Methoxyethyl methacrylate HEA: 2-Hydroxyethyl Acrylate HPA: 2-Hydroxypropyl acrylate GMA: Glycidyl methacrylate PhOEtA: 2-Phenoxyethyl acrylate

[0104] [Table 1]

[0105] [Preparation of antifouling coating composition][ [Example 1][ The antifouling paint composition was prepared as follows. In a plastic container, 11.3 parts xylene, 1 part aromatic hydrocarbon mixture (Solvesso 150), 4 parts gum rosin (Chinese gum rosin WW), 0.5 parts alkoxysilane (ethyl silicate 28), 12 parts silyl ester copolymer solution (A-1), and 8 parts copolymer solution (B-1) were added and mixed using a paint shaker until each component was uniformly dispersed or dissolved. Subsequently, 7 parts talc (FC-1), 7 parts zinc oxide (three types of zinc oxide), 9.5 parts barium sulfate (precipitating barium sulfate 100), 35 parts cuprous oxide (NORDOX), 0.7 parts red iron oxide (TODA COLOR NM-50), 1 part titanium dioxide (Typake R-930), 1 part copper pyrithione (Copper Omadine Powder), 1 part polyethylene oxide (Disparon 4200-20X), and 150 parts glass beads were added to a poly container and stirred with a paint shaker for 1 hour to disperse these components. After dispersion, 1 part fatty acid amide (Disparon A630-20X) was added and stirred with a paint shaker for 20 minutes. Then, the glass beads were removed from the mixture using a filter (mesh size: 80 mesh) to obtain an antifouling paint composition.

[0106] [Examples 2 to 20][ An antifouling coating composition was prepared in the same manner as in Example 1, except that the types and amounts of each component were changed as shown in Table 2.

[0107] [Comparative examples 1 to 7][ An antifouling coating composition was prepared in the same manner as in Example 1, except that the types and amounts of each component were changed as shown in Table 3. In Tables 2 and 3, (A), (B), and (cB) represent the amounts of copolymer solution used.

[0108] [Physical property evaluation of antifouling coating composition][ The physical properties of the coating films formed using the antifouling coating compositions obtained in the examples and comparative examples were evaluated as follows. The results are shown in Tables 2 and 3.

[0109] <Static antifouling property test>[ An epoxy-based anticorrosive coating (product name "Banno 500", manufactured by Chugoku Marine Paints Co., Ltd.) was applied to a sandblasted steel plate (300mm x 100mm x 2.3mm) using an air spray to a dry film thickness of 150μm, and dried at 23°C for one week to form a hardened coating. Next, a vinyl-based binder coating (product name "Silvacs SQ-K", manufactured by Chugoku Marine Paints Co., Ltd.) was applied to the hardened coating using an air spray to a dry film thickness of 40μm, and dried at 23°C for 24 hours.

[0110] Next, each antifouling coating composition prepared in the examples or comparative examples was applied to the surface of the dried coating film formed from the vinyl binder coating to a dry film thickness of 200 μm, and then dried at 23°C for 7 days to form an antifouling coating film, thereby preparing a static antifouling test plate.

[0111] The prepared static antifouling test plates were suspended and immersed in the Seto Inland Sea off the coast of Hatsukaichi City, Hiroshima Prefecture, at a depth of 400 mm or less, and left in a static state. At 6, 12, 24, and 36 months from the start of immersion, the area of ​​the antifouling coating on the antifouling coating (hereinafter also referred to as "adhesion area") (%) was measured, with the total area of ​​the antifouling coating in the part of the test plate constantly submerged in seawater being set to 100%. The static antifouling performance was evaluated based on the evaluation criteria below.

[0112] (Evaluation criteria)[ 5: The adhesion area is less than 5%. 4: The adhesion area is 5% or more and less than 20%. 3: The adhesion area is 20% or more, but less than 50%. 2: The adhesion area is 50% or more, but less than 70%. 1: The adhesion area is 70% or more.

[0113] <Coating film crack resistance (water resistance) test>[ An epoxy-based anticorrosive coating (product name "Banno 500", manufactured by Chugoku Marine Paints Co., Ltd.) was applied to a sandblasted steel plate (150mm x 70mm x 1.6mm) using an air spray to a dry film thickness of 150μm, and dried at 23°C for one week to form a cured coating. Next, a vinyl-based binder coating (product name "Silvacs SQ-K", manufactured by Chugoku Marine Paints Co., Ltd.) was applied to the cured coating using an air spray to a dry film thickness of 40μm, and dried at 23°C for 24 hours.

[0114] Next, each antifouling coating composition prepared in the examples or comparative examples was applied to the surface of the dried coating film formed from the vinyl binder coating to a dry film thickness of 300 μm, and then dried at 23°C for 7 days to form an antifouling coating film, and a test plate was prepared.

[0115] The above test plates were immersed in artificial seawater at 50°C, and the appearance of the coating was inspected every month for six months. The artificial seawater was replaced with fresh water every week. The crack resistance of the coating was evaluated based on the following evaluation criteria (i.e., the ratio of the crack area to the total surface area of ​​the coating).

[0116] (Evaluation criteria)[ 5: In cases where there are absolutely no abnormalities. 4: Cracks were observed in less than 10% of the total surface area of ​​the coating. 3: Cracks are observed on 10% or more but less than 30% of the total surface area of ​​the coating. 2: Cracks are observed on 30% or more but less than 50% of the total surface area of ​​the coating. 1: Cracks are observed in more than 50% of the total surface area of ​​the coating.

[0117] [Table 2]

[0118] [Table 3]

[0119] The details of the components used in the examples and comparative examples are as follows. [Table 4]

[0120] When copolymers containing HEA or HPA units were used instead of MEA units, short-term antifouling and crack resistance were observed, but long-term antifouling and crack resistance were poor. This is presumed to be because HEA and HPA are too hydrophilic compared to MEA.

[0121] When copolymers containing GMA units instead of MEA units were used, long-term antifouling properties tended to be lower. This is presumed to be because GMA units have lower hydrophilicity compared to MEA units, resulting in insufficient hydrolysis of the silyl ester polymer.

[0122] When copolymers containing MEMA units instead of MEA units were used, the antifouling properties were poor. This is presumed to be because MEMA units are more hydrophobic than MEA units, inhibiting the hydrolysis reaction of silyl ester polymers.

[0123] When copolymers having MMA units or BA units instead of St units were used, the stain resistance and crack resistance were poor. Compared to the comparative examples above, the copolymer containing St and MEA units exhibited significantly superior long-term antifouling and crack resistance. Although the reason is not entirely clear, it is presumed that incorporating a copolymer of St and MEA into a silyl ester polymer resulted in a particularly good balance between the hydrophobicity and hydrophilicity of the antifouling coating.

Claims

1. a silyl ester polymer (A); a copolymer (B) having a structural unit (b-1) derived from styrene and a structural unit (b-2) derived from a polymerizable monomer (b2) represented by formula (b2); An antifouling coating composition comprising: Formula (b2): CH2=CH-COO-(R b1 -O) n -R b2 [In formula (b2), R b1 is an alkanediyl group having 1 to 5 carbon atoms, and R b2 is an alkyl group having 1 to 5 carbon atoms, and n is an integer of 1 to 3.

2. 2. The antifouling coating composition according to claim 1, wherein the proportion of the structural unit (b-1) in the copolymer (B) is 30 to 80 mass %.

3. 3. The antifouling coating composition according to claim 1, wherein the proportion of the structural unit (b-2) in the copolymer (B) is 15 to 45 mass %.

4. 4. The antifouling coating composition according to claim 1, wherein the polymerizable monomer (b2) represented by formula (b2) is an alkoxyalkyl acrylate.

5. 5. The antifouling coating composition according to claim 4, wherein the polymerizable monomer (b2) represented by formula (b2) is 2-methoxyethyl acrylate.

6. 6. The antifouling coating composition according to claim 1, wherein the silyl ester polymer (A) has a structural unit derived from triisopropylsilyl methacrylate.

7. 7. The antifouling coating composition according to claim 1, wherein the mass ratio (A:B) of the silyl ester polymer (A) to the copolymer (B) is 90:10 to 30:

70.

8. 8. The antifouling coating composition according to claim 1, further comprising a monocarboxylic acid compound (C).

9. 9. The antifouling coating composition according to claim 1, further comprising copper and / or a copper compound (D).

10. 10. The antifouling coating composition according to claim 1, further comprising an organic antifouling agent (E).

11. An antifouling coating film formed from the antifouling coating composition according to any one of claims 1 to 10.

12. A substrate; The antifouling coating film according to claim 11 provided on the surface of the substrate; A substrate with an antifouling coating film having the above structure.

13. 13. The substrate with an antifouling coating film according to claim 12, wherein the substrate is at least one selected from ships, underwater structures, fishing equipment, and water supply and drainage pipes.

14. 11. A method for producing a substrate with an antifouling coating film, comprising the step of applying or impregnating a substrate with the antifouling coating composition according to claim 1.