Underwater antifouling paint composition and method for producing antifouling coating film

Abstract

To provide an underwater antifouling coating composition on which a riblet structure can be formed by laser irradiation of the resulting coating film. Furthermore, to provide a method for manufacturing an antifouling coating film using the antifouling coating composition. [Solution] [1] An underwater antifouling coating composition for coating films that forms a riblet structure by laser irradiation, containing a curable organopolysiloxane (A). A method for producing an antifouling coating film having a riblet structure on its surface, comprising the following steps (1) and (2) in this order. Step (1): A step of forming an antifouling coating film on a substrate using the underwater antifouling coating composition described in [1] above. Step (2): A step of irradiating the surface of the antifouling coating with a laser to form a riblet structure.

Description

[Technical Field]

[0001] This invention relates to an underwater antifouling coating composition and a method for producing an antifouling coating film using the same. [Background technology]

[0002] To reduce the propulsion resistance of ships, it is necessary to prevent the attachment of marine organisms, and antifouling paints for ship bottoms are widely used. In recent years, methods to further reduce water flow friction by forming microstructures such as regular groove shapes on the surface have been investigated. Patent Document 1 describes an antifouling coating film containing a binder (A) and a specific biological repellent (B), and having a riblet structure on its surface, with the aim of providing an antifouling coating film and a method for producing the same, a water intake structure with an antifouling coating film, and an antifouling tape and a method for producing the same, in which the elution of a biological repellent is suppressed when exposed to a dynamic water flow in water, and the antifouling coating film exhibits antifouling properties over a long period of time. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] International Publication No. 2019 / 189412 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] However, the embodiment in Patent Document 1 employs a method using a mold, but this method requires the step of applying antifouling paint to the object to be coated and then pressing the mold against it. In this case, there is a problem that air bubbles may get mixed in between the applied antifouling paint and the mold, making it difficult to form the desired shape, and there is also the problem that using a mold requires resources and costs. In view of these challenges, the present invention aims to provide an underwater antifouling coating composition on which a riblet structure can be formed by laser irradiation of the obtained coating film. Furthermore, the present invention aims to provide a method for manufacturing an antifouling coating film using the antifouling coating composition. [Means for solving the problem]

[0005] As a result of diligent research by the inventors, we have found that the above problems can be solved by using the antifouling coating composition shown below, and have completed the present invention. The gist of this invention is as follows:

[0006] The present invention relates to the following [1] to

[15] . [1] An underwater antifouling coating composition for coating films containing a curable organopolysiloxane (A), which forms a riblet structure upon laser irradiation. [2] The underwater antifouling paint composition according to [1], wherein the underwater antifouling paint composition contains an organosilicon crosslinking agent (B), and the amount of organosilicon crosslinking agent (B) is 1 part by mass or more and 15 parts by mass or less per 100 parts by mass of curable organopolysiloxane (A). [3] The underwater antifouling paint composition according to [1] or [2], wherein the underwater antifouling paint composition contains an organosilicon crosslinking agent (B), and the organosilicon crosslinking agent (B) contains oximsilane. [4] The underwater antifouling paint composition according to any one of [1] to [3], wherein the underwater antifouling paint composition contains an inorganic filler (C), and the total content of the inorganic filler (C) is 5 parts by mass or more and 60 parts by mass or less per 100 parts by mass of curable organopolysiloxane (A). [5] The underwater antifouling paint composition according to any one of [1] to [4], wherein the underwater antifouling paint composition contains silica as an inorganic filler (C), and the silica content is 1 part by mass or more and 30 parts by mass or less per 100 parts by mass of curable organopolysiloxane (A). [6] The underwater antifouling paint composition according to any one of [1] to [5], wherein the underwater antifouling paint composition contains a pigment containing a component derived from Fe as an inorganic filler (C), and the content of the pigment containing the component derived from Fe is 1 part by mass or more and 30 parts by mass or less per 100 parts by mass of curable organopolysiloxane (A). [7] The underwater antifouling paint composition according to any one of [1] to [6], wherein the underwater antifouling paint composition contains at least one selected from yellow iron oxide, red iron oxide, and black iron oxide as an inorganic filler (C), and the total content of yellow iron oxide, red iron oxide, and black iron oxide is 1 part by mass or more and 30 parts by mass or less per 100 parts by mass of curable organopolysiloxane (A). [8] The underwater antifouling paint composition according to any one of [1] to [7], wherein the underwater antifouling paint composition contains an inorganic filler other than titanium dioxide as an inorganic filler (C), and the amount of the inorganic filler other than titanium dioxide is 1 part by mass or more and 30 parts by mass or less per 100 parts by mass of curable organopolysiloxane (A). [9] The underwater antifouling paint composition according to any one of [1] to [8], wherein the detection frequency of particles with a particle diameter of 20 μm or more is 10% or less of the total particles contained in the underwater antifouling paint composition.

[10] The underwater antifouling paint composition according to any one of [1] to [9], wherein the underwater antifouling paint composition contains a slip agent (D), and the amount of slip agent (D) is 5 parts by mass or more and 120 parts by mass or less per 100 parts by mass of curable organopolysiloxane (A).

[11] The antifouling paint composition according to

[10] , wherein the slip agent (D) contains one or more selected from the group consisting of silicone oil (D1) and polymers (D2) containing constituent units derived from hydrophilic group-containing unsaturated monomers.

[12] The underwater antifouling paint composition according to

[11] , wherein the content of a polymer (D2) containing constituent units derived from a hydrophilic group-containing unsaturated monomer is 10 parts by mass or less per 100 parts by mass of a curable organopolysiloxane (A).

[13] A method for manufacturing an antifouling coating having a riblet structure on its surface, comprising the following steps (1) and (2) in this order. Step (1): A step of forming an antifouling coating film on a substrate using the underwater antifouling coating composition described in any one of [1] to

[12] . Step (2): A step of irradiating the surface of the antifouling coating with a laser to form a riblet structure.

[14] A method for manufacturing an antifouling coating according to

[13] , wherein the riblet depth of the riblet structure is 1 μm or more and 100 μm or less.

[15] The method for manufacturing an antifouling coating according to

[13] or

[14] , wherein the substrate is a ship. [Effects of the Invention]

[0007] The present invention provides an underwater antifouling coating composition on which a riblet structure can be formed by laser irradiation of the resulting coating film. Furthermore, the present invention provides a method for manufacturing an antifouling coating film using the antifouling coating composition. [Modes for carrying out the invention]

[0008] The following describes in detail the antifouling paint composition and the method for producing the antifouling coating film according to the present invention. In the following explanation, "(meth)acryloyl," "(meth)acrylic acid," and "(meth)acrylate" mean "acryloyl or methacryloyl," "acrylic acid or methacrylic acid," and "acrylate or methacrylate," respectively.

[0009] [Antifouling paint composition] The underwater antifouling coating composition for coating films that form a riblet structure by laser irradiation according to the present invention (hereinafter also simply referred to as "antifouling coating composition") contains a curable organopolysiloxane (A). The antifouling coating film formed from the underwater antifouling coating composition of this embodiment can form a riblet structure by laser irradiation and is suitable for the formation of a riblet structure by laser irradiation. Although the detailed mechanism by which the above effects are obtained is not entirely clear, some aspects are presumed to be as follows. In other words, the siloxane bonds (-Si-O-Si-) in the curable organopolysiloxane (A), which is a resin constituting the antifouling paint composition, have high bond energy. As a result, even when the paint film is irradiated with a laser, only the irradiated portion is removed, which is thought to be how a finer riblet structure can be obtained by laser irradiation. The following describes in detail each component contained in the antifouling coating composition of the present invention.

[0010] <Curing organopolysiloxane (A)> The antifouling coating composition of this embodiment contains a curable organopolysiloxane (A). Examples of such curable organopolysiloxanes (A) include those having reactive groups in the molecule, which harden by forming a three-dimensional crosslinked structure through the reaction of these reactive groups with each other or with the reactive groups of the organosilicon crosslinking agent (B) described later. Examples of reactions of these reactive groups include condensation reactions and addition reactions, and examples of condensation reactions include de-alcoholization reactions, de-oxime reactions, and de-acetone reactions.

[0011] As for the curable organopolysiloxane (A), it is preferable that it forms silicone rubber when cured, from the viewpoint of ease of forming a riblet structure on the coating film by laser irradiation, for example, a compound represented by the following formula (A1) is preferred.

[0012] [ka]

[0013] In formula (A1), R 11 and R 13 Each of these independently represents a hydrogen atom, a C1-C16 alkyl group, a C2-C16 alkenyl group, a C6-C16 aryl group, a C7-C16 aralkyl group, or a C1-C16 halogenated alkyl group, R 12 Each of these independently represents either a hydroxyl group or a hydrolyzable group. Furthermore, r represents an integer from 1 to 3, and p represents a value from 10 to 10,000.

[0014] R 11 and R 13Examples of the alkyl group having 1 to 16 carbon atoms in [description] include linear or branched ones, such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, decyl group, dodecyl group, hexadecyl group and the like. R 11 and R 13 Examples of the alkenyl group having 2 to 16 carbon atoms in [description] include linear, branched or cyclic ones, such as vinyl group, allyl group, propenyl group, isopropenyl group, butenyl group, isobutenyl group, pentenyl group, heptenyl group, hexenyl group, cyclohexenyl group, octenyl group, decenyl group, dodecenyl group and the like.

[0015] R 11 and R 13 Examples of the aryl group having 6 to 16 carbon atoms in [description] may have a substituent such as an alkyl group on the aromatic ring, and examples thereof include phenyl group, tolyl group (methylphenyl group), xylyl group (dimethylphenyl group), naphthyl group and the like. R 11 and R 13 Examples of the aralkyl group having 7 to 16 carbon atoms in [description] include benzyl group, 2-phenylethyl group, 2-naphthylethyl group, diphenylmethyl group and the like. R 11 and R 13 Examples of the halogenated alkyl group having 1 to 16 carbon atoms in [description] include groups in which some or all of the hydrogen atoms contained in the alkyl group are replaced by halogen atoms such as fluorine atom, chlorine atom, bromine atom and iodine atom.

[0016] Among these, R in formula (A1) 11 is preferably the alkyl group, the alkenyl group or the aryl group, more preferably methyl group, ethyl group, vinyl group or phenyl group, and still more preferably methyl group or vinyl group. Also, R in formula (A1) 13The alkyl group, the alkenyl group, and the aryl group are preferred, the methyl group, ethyl group, vinyl group, and phenyl group are more preferred, the methyl group, ethyl group, and phenyl group are even more preferred, and the methyl group and phenyl group are even more preferred. Note that there are multiple R 13 These may be the same or different. Also, R 11 When multiple instances exist, they may be identical or different.

[0017] R in the above formula (A1) 12 Each of these independently represents either a hydroxyl group or a hydrolyzable group. R 12 Examples of hydrolyzable groups in this context include oxime groups, acyloxy groups, alkoxy groups, alkenyloxy groups, amino groups, amide groups, and aminooxy groups. R 12 The oxime group in is preferably an oxime group having 1 to 10 carbon atoms, such as a dimethyl ketoxime group, a methyl ethyl ketoxime group, a diethyl ketoxime group, and a methyl isopropyl ketoxime group.

[0018] R 12 The acyloxy group (RC(=O)O-) in this compound is preferably an aliphatic acyloxy group having 1 to 10 carbon atoms, or an aromatic acyloxy group having 7 to 12 carbon atoms, such as an acetoxy group, a propionyloxy group, a butyryloxy group, and a benzoyloxy group.

[0019] R 12 In R, an alkoxy group having 1 to 10 carbon atoms is preferred. 12 In this case, the alkoxy group may have an ether group (-O-) interposed between the carbon-carbon bonds of the alkyl chain. R 12 Specific examples of alkoxy groups in this context include methoxy, ethoxy, propoxy, butoxy, methoxyethoxy, and ethoxyethoxy groups. R 12The alkenyloxy group in this is preferably an alkenyloxy group having 3 to 10 carbon atoms, such as isopropenyloxy, isobutenyloxy, and 1-ethyl-2-methylvinyloxy.

[0020] R 12 The amino group in this compound may be a primary amino group, a secondary amino group, or a tertiary amino group, with secondary and tertiary amino groups being preferred, and amino groups having 1 to 10 carbon atoms being more preferred. Examples of preferred amino groups include N-methylamino group, N-ethylamino group, N-propylamino group, N-butylamino group, N,N-dimethylamino group, N,N-diethylamino group, and N-cyclohexylamino group. In this specification, a primary amino group refers to a group represented by -NH2, a secondary amino group refers to a group in which one hydrogen atom of -NH2 is replaced by an alkyl group or the like, and a tertiary amino group refers to a group in which two hydrogen atoms of -NH2 are replaced by alkyl groups or the like.

[0021] R 12 The amide group in this is preferably an amide group having 2 to 10 carbon atoms, such as N-methylacetamide, N-ethylacetamide, and N-methylbenzamide.

[0022] R 12 The aminooxy group in is preferably an aminooxy group having 2 to 10 carbon atoms, such as the N,N-dimethylaminooxy group and the N,N-diethylaminooxy group.

[0023] Among these, R in equation (A1) 12 The group is preferably a hydroxyl group, an oxime group, or an alkoxy group, more preferably a hydroxyl group and an oxime group, and even more preferably a hydroxyl group, a methyl ethyl ketoxime group, or a methyl isobutyl ketoxime group. Note that there are multiple R 12 These may be the same or different.

[0024] In equation (A1), r represents an integer between 1 and 3. R 12 When is a hydroxyl group, r is preferably 1, R 12 If the substituent is not a hydroxyl group, r is preferably 2. In formula (A1), p is between 10 and 10,000, preferably between 100 and 1,000, and can be appropriately adjusted to satisfy the following weight-average molecular weight. Note that p is -(SiR 13 This refers to the average number of repetitions of (2-O).

[0025] The weight-average molecular weight (Mw) of the curable organopolysiloxane (A) is preferably 500 or more, more preferably 5,000 or more, even more preferably 10,000 or more, even more preferably 15,000 or more, even more preferably 20,000 or more, and preferably 1,000,000 or less, more preferably 100,000 or less, even more preferably 50,000 or less, and even more preferably 40,000 or less, from the viewpoint of ease of forming a riblet structure on the coating film by laser irradiation, from the viewpoint of improving workability during the manufacture of the paint composition, and from the viewpoint of improving the paint workability, curability, and strength and flexibility of the formed coating film.

[0026] In the present invention, the "weight-average molecular weight (Mw)" of curable organopolysiloxane (A) and polymers (D2) containing constituent units derived from hydrophilic group-containing unsaturated monomers, as described later, is measured using GPC (gel permeation chromatography) and calculated by converting it to standard polystyrene with a known molecular weight.

[0027] The viscosity of the curable organopolysiloxane (A) at 23°C is preferably 20 mPa·s or more, more preferably 100 mPa·s or more, even more preferably 500 mPa·s or more, and preferably 100,000 mPa·s or less, more preferably 10,000 mPa·s or less, and even more preferably 8,000 mPa·s or less, from the viewpoint of ease of forming a riblet structure on the coating film by laser irradiation, from the viewpoint of improving workability during the manufacture of the paint composition, and from the viewpoint of improving the paint workability, curability, and strength and flexibility of the formed coating film of the paint composition. In this specification, the viscosity of a curable organopolysiloxane at 23°C refers to the viscosity measured using a Type B rotational viscometer (for example, Model: BM, manufactured by Tokyo Keiki Co., Ltd.).

[0028] The content of curable organopolysiloxane (A) in the antifouling coating composition according to the present invention is preferably 10% by mass or more, more preferably 20% by mass or more, even more preferably 30% by mass or more, and preferably 90% by mass or less, more preferably 70% by mass or less, and even more preferably 60% by mass or less, from the viewpoint of improving the strength and flexibility of the formed coating film and from the viewpoint of facilitating the formation of a riblet structure in the coating film by laser irradiation.

[0029] Furthermore, the content of curable organopolysiloxane (A) in the solid content of the antifouling coating composition is preferably 15% by mass or more, more preferably 25% by mass or more, even more preferably 35% by mass or more, and preferably 95% by mass or less, more preferably 85% by mass or less, even more preferably 80% by mass or less, and even more preferably 75% by mass or less. In this specification, "solid content of the antifouling coating composition" refers to the components excluding the organic solvent (J) described later and the volatile components contained as solvents in each component, and "content in the solid content of the antifouling coating composition" can be calculated as the content in the solid content obtained by drying the antifouling coating composition in a hot air dryer at 125°C for 1 hour.

[0030] The content of curable organopolysiloxane (A) in the binder-forming component is preferably 50% by mass or more, more preferably 80% by mass or more, and even more preferably 95% by mass or more, from the viewpoint of improving the stain resistance of the coating film and the ease of forming a riblet structure. The upper limit of the content is not particularly limited, i.e., 100% by mass. The binder-forming component may consist only of curable organopolysiloxane (A).

[0031] As the curable organopolysiloxane, commercially available products can be used. Examples of commercially available products include "DMS-S35" manufactured by GELEST and "KE-445" manufactured by Shin-Etsu Chemical Co., Ltd. Alternatively, the curable organopolysiloxane described in Japanese Patent Publication No. 2001-139816 can also be used.

[0032] The antifouling coating composition of this embodiment preferably contains various components in addition to the curable organopolysiloxane (A) described above. Examples include organosilicon crosslinking agents (B), inorganic fillers (C), slip agents (D), silane coupling agents (E), biological repellents (F), and organic solvents (J). Other examples of components include curing catalysts (G), dehydrating agents (H), anti-sagging and anti-settlement agents (K), enzymes (L), flame retardants (M), and heat conduction improvers (N). <Organosilicon crosslinking agent (B)> The antifouling coating composition of this embodiment may, and preferably may, contain an organosilicon crosslinking agent (B) from the viewpoint of improving the curability and strength of the antifouling coating film, and from the viewpoint of facilitating the formation of a riblet structure on the coating film by laser irradiation. The organosilicon crosslinking agent (B) is preferably a compound represented by the following formula (B1) and / or a partial condensate thereof, from the viewpoint of improving the storage stability of the antifouling coating composition, the ability to prevent skinning of the coating surface (liquid surface) due to moisture, and the manufacturing stability when applying the coating.

[0033] R 51 d SiY (4-d) (B1) In formula (B1), R51 represents a hydrocarbon group having 1 to 6 carbon atoms, Y independently represents a hydrolyzable group, and d represents an integer from 0 to 2.

[0034] R in equation (B1) 51 This represents a monovalent hydrocarbon group having 1 to 6 carbon atoms, and examples include linear or branched alkyl groups such as methyl, ethyl, and propyl groups, cyclic alkyl groups such as cyclohexyl groups, alkenyl groups such as vinyl groups, or aryl groups such as phenyl groups. Among these, methyl, ethyl, and vinyl groups are preferred. Note that when d is 2, there are multiple R 51 These may be the same or different. In formula (B1), Y independently represents a hydrolyzable group, and examples of hydrolyzable groups include those exemplified in formula (A1). Among these, alkoxy groups and oxime groups are preferred. The alkoxy group is preferably a methoxy group and an ethoxy group. The number of carbon atoms in the alkyl group of the ketoxime group (dialkylketoxime group) is preferably 1 to 6, more preferably 1 to 4. The ketoxime group is preferably a methyl ethyl ketoxime group and a methyl isobutyl ketoxime group. The multiple Ys may be the same or different. The organosilicon crosslinking agent (B) preferably contains at least a compound (oximesilane) in which Y in formula (B1) is a ketoxime group and / or a partial condensate thereof, and more preferably contains oximesilane. In addition to the oximesilane, it may also contain a compound (alkoxysilane) in which Y in formula (B1) is an alkoxy group and / or a partial condensate thereof. Using oximesilane and alkoxysilane and / or a partial condensate thereof in combination is preferred from the viewpoint of improving the curability and strength of the antifouling coating film and from the viewpoint of facilitating the formation of a riblet structure on the coating film by laser irradiation. In formula (B1), d represents an integer from 0 to 2, and 0 or 1 is preferred from the viewpoint of improving the curability and film strength of the antifouling coating and from the viewpoint of facilitating the formation of a riblet structure on the coating by laser irradiation. When Y in formula (B1) is an oxime group, d is more preferably 1, and when Y in formula (B1) is an alkoxy group, d is more preferably 0.

[0035] As the organosilicon crosslinking agent (B), commercially available products can be used. Examples of commercially available products include, for example, "Ethyl Silicate 28" manufactured by Colcoat and "Ethyl Orthosilicate" manufactured by Tama Chemical Industry Co., Ltd. as tetraethyl orthosilicate (tetraethoxysilane). Examples of partially hydrolyzed condensates of tetraethyl orthosilicate (tetraethoxysilane) include "Silicate 40" manufactured by Tama Chemical Industry Co., Ltd. and "WACKER SILICATE TES 40WN" manufactured by Asahi Kasei Wacker Silicone Co., Ltd. Examples of alkyltrialkoxysilanes include "KBM-13" manufactured by Shin-Etsu Chemical Co., Ltd. Examples of oximesilanes include "MTO(MOS)" (methyltris(methylethylketoxime)silane) and "VTO(VOS)" (vinyltris(methylethylketoxime)silane) manufactured by Toray Industries, Inc., and "X-93-4096" (vinyltris(methylisobutylketoxime)silane) manufactured by Shin-Etsu Chemical Co., Ltd. The organosilicon crosslinking agent (B) may be used alone or in combination of two or more types.

[0036] In the antifouling coating composition of this embodiment, the content of the organosilicon crosslinking agent (B) is preferably 1 to 15 parts by mass, more preferably 1.5 parts by mass or more, even more preferably 2 parts by mass or more, even more preferably 10 parts by mass or less, even more preferably 7 parts by mass or less, and even more preferably 5 parts by mass or less, from the viewpoint of adjusting the curing speed of the coating film, improving the strength of the coating film, facilitating the formation of a riblet structure on the coating film by laser irradiation, and maintaining the antifouling properties of the coating film in which a riblet structure has been formed by laser irradiation, per 100 parts by mass of curable organopolysiloxane (A). Furthermore, from a similar viewpoint, the content of organosilicon crosslinking agent (B) in the solid content of the antifouling coating composition of this embodiment is preferably 0.5% by mass or more and 20% by mass or less, more preferably 1.0% by mass or more, even more preferably 1.5% by mass or more, and even more preferably 10% by mass or less, even more preferably 5% by mass or less, and even more preferably 3% by mass or less.

[0037] <Inorganic filler (C)> The antifouling coating composition of this embodiment preferably contains an inorganic filler (C) from the viewpoint of improving the fluidity and thixotropy of the coating composition, and from the viewpoint of facilitating the formation of a riblet structure on the coating film by laser irradiation. When the antifouling coating composition of this embodiment contains an inorganic filler (C), as described above, the fluidity and thixotropy of the antifouling coating composition are improved, and a coating of sufficient thickness can be formed on vertical painted surfaces with fewer coats. Furthermore, the physical properties of the antifouling coating, such as hardness, tensile strength, and elongation, can be improved in a balanced manner. In addition, the ease of forming a riblet structure on the coating by laser irradiation is improved. From the above viewpoint, in the antifouling coating composition of this embodiment, the total content of inorganic filler (C) is preferably 5 parts by mass or more and 60 parts by mass or less, more preferably 10 parts by mass or more, even more preferably 20 parts by mass or more, and even more preferably 50 parts by mass or less, even more preferably 45 parts by mass or less, and even more preferably 40 parts by mass or less, based on 100 parts by mass of curable organopolysiloxane (A). Furthermore, the total content of inorganic filler (C) in the solid content of the antifouling coating composition is preferably 2% by mass or more, more preferably 5% by mass or more, even more preferably 10% by mass or more, and preferably 30% by mass or less, more preferably 25% by mass or less, and even more preferably 20% by mass or less, from the viewpoint described above.

[0038] The average particle size of the inorganic filler (C) is preferably 5 μm or less, more preferably 1 μm or less, and even more preferably 0.7 μm or less, from the viewpoint of ease of forming a riblet structure on the coating film by laser irradiation and from the viewpoint of forming a riblet structure of a desired shape. Furthermore, from the viewpoint of improving physical properties such as hardness, tensile strength, and elongation in the antifouling coating film, it is preferably 10 μm or less, more preferably 3 μm or less, and even more preferably 1 μm or less. The lower limit is not particularly limited, but from the viewpoint of availability, ease of handling, and low paint viscosity, it is preferably 0.001 μm or more, and more preferably 0.01 μm or more. If the average particle size of the inorganic filler (C) exceeds 5 μm, it tends to be difficult to obtain a fine riblet structure. The average particle size of the inorganic filler (C) is measured by adding an appropriate amount of the inorganic filler to the circulator of a laser diffraction particle size distribution analyzer (Microtrac-Bell Co., Ltd., MT-3300EXII) to adjust the concentration to the appropriate level, dispersing it for 10 minutes using the ultrasonic disperser built into the device, acquiring the data, and calculating it using the refractive index of the inorganic filler. Depending on the type of inorganic filler being measured, an appropriate dispersant may be used during ultrasonic dispersion. Alternatively, the inorganic filler (C) can be measured by visual observation using a laser microscope or the like. However, for example, in the case of a flattened inorganic filler, it refers to the maximum length on the main surface (the surface with the largest area) of the inorganic filler; if the main surface is square, it refers to the length of the diagonal; if it is circular, it refers to the diameter; and if it is elliptical, it refers to the length of the major axis. Furthermore, catalog values ​​may be used for the average particle size of the inorganic filler (C). When using multiple types of inorganic fillers (C), the average particle size of the inorganic fillers (C) is calculated by either measuring the average particle size of the mixture or by multiplying the average particle size of each by its occupying volume ratio within the inorganic fillers (C) and adding them together.

[0039] Examples of inorganic fillers (C) include silica, mica, calcium carbonate, aluminum carbonate, magnesium carbonate, barium carbonate, aluminum oxide, aluminum hydroxide, aluminum silicate, magnesium silicate, potassium feldspar, zinc oxide, kaolin, alumina white, barium sulfate, calcium sulfate, zinc sulfide, pigments containing components derived from Fe, and glass short fibers. These inorganic fillers may be used individually or in combination of two or more types.

[0040] Among these, the inorganic filler (C) preferably contains silica, from the viewpoint of improving the physical properties such as hardness, tensile strength, and elongation of the resulting antifouling coating film in a balanced manner, and from the viewpoint of facilitating the formation of a riblet structure in the coating film by laser irradiation. As silica, hydrophilic silica (surface-untreated silica) such as wet-process silica (hydrated silica) and dry-process silica (fumed silica, anhydrous silica) can be used. Alternatively, hydrophobic silica, specifically hydrophobic wet-process silica and hydrophobic fumed silica, whose surfaces have been hydrophobically treated, can also be used. These silicas may be used individually or in combination of two or more types.

[0041] There are no particular restrictions on the wet-process silica, but for example, it may have an adsorbed water content of 4-8% by mass, a bulk density of 200-300 g / L, a primary particle size of 10-30 nm, and a specific surface area (BET surface area) of 10 m². 2 Wet-processed silica with a content of 1 / g or more is preferred. Furthermore, there are no particular restrictions on the dry-process silica, but for example, it may have a moisture content of 1.5% by mass or less, a bulk density of 50-100 g / L, a primary particle size of 8-20 nm, and a specific surface area of ​​10 m². 2 Dry-processed silica of 1 / g or more is preferred.

[0042] Examples of the hydrophobic fumed silica include silica prepared by dry process, surface-treated with one or more organosilicon compounds selected from methyltrichlorosilane, dimethyldichlorosilane, hexamethyldisilazane, hexamethylcyclotrisiloxane, and octamethylcyclotetrasiloxane. Hydrophobic fumed silica exhibits low moisture adsorption over time, and its moisture content is preferably 0.3% by mass or less, more preferably 0.1 to 0.2% by mass. There are no particular limitations on the hydrophobic fumed silica, but for example, it may have a primary particle size of 5-50 nm, a bulk density of 50-100 g / L, and a specific surface area of ​​10 m². 2 Hydrophobic fumed silica with a content of 1 / g or more is preferred. Note that when hydrophobic fumed silica is subjected to the heat treatment described later, the moisture content adsorbed on the surface of the hydrophobic fumed silica after heat treatment may decrease. In that case, the moisture content of the hydrophobic fumed silica is preferably 0.2% by mass or less, more preferably 0.1% by mass or less, and even more preferably 0.05 to 0.1% by mass.

[0043] Such silica can be commercially available. Examples of commercially available products include "AEROSIL R974," "AEROSIL RX200," and "AEROSIL 200" manufactured by Nippon Aerosil Co., Ltd. In addition, the silica described in Japanese Patent Publication No. 2001-139816 can also be used.

[0044] In this embodiment, silica may be a heat-treated product obtained by pre-heat-treating it together with a curable organopolysiloxane (A). By pre-heat-treating part or all of the silica and the curable organopolysiloxane (A), the affinity between the two components is improved, and effects such as suppressing silica aggregation can be obtained. A method for heat-treating silica and a curable organopolysiloxane includes, for example, a method of treatment under normal pressure or reduced pressure, preferably at a temperature of 100°C or higher, below the decomposition temperature of the compounding components, more preferably 100 to 300°C, and even more preferably 140 to 200°C, for 3 to 30 hours.

[0045] Furthermore, silica may be incorporated into the antifouling paint composition as a compound obtained by kneading it together with a curable organopolysiloxane (A). By using a compound obtained by kneading a curable organopolysiloxane and silica, it is possible to suppress an excessive increase in the viscosity of the antifouling paint composition. For example, a method for producing a compound of silica and a curable organopolysiloxane (A) can be described in Japanese Patent Publication No. 2004-182908.

[0046] When the antifouling coating composition of this embodiment contains silica as an inorganic filler (C), the silica content per 100 parts by mass of curable organopolysiloxane (A) is preferably 1 part by mass or more, more preferably 3 parts by mass or more, even more preferably 5 parts by mass or more, even more preferably 8 parts by mass or more, and even more preferably 10 parts by mass or more, from the viewpoint of improving the thixotropy of the antifouling coating composition, improving the strength and hardness of the coating film, having excellent coating film formation properties, and facilitating the formation of riblet structures on the coating film by laser irradiation. Furthermore, from the viewpoint of suppressing an excessive increase in the viscosity of the antifouling coating composition, it is preferably 30 parts by mass or less, more preferably 25 parts by mass or less, even more preferably 20 parts by mass or less, and even more preferably 15 parts by mass or less.

[0047] In this embodiment, it is preferable to include an inorganic filler other than titanium dioxide as the inorganic filler (C). When a fiber laser is used as the laser, it is preferable to include a filler other than titanium dioxide, particularly an inorganic filler that absorbs at the laser wavelength, from the viewpoint of facilitating the formation of riblet structures on the coating film by laser irradiation, facilitating the formation of finer riblet structures, and maintaining the antifouling properties of the coating film in which riblet structures have been formed by laser irradiation. When a CO2 laser is used as the laser, since the curable organopolysiloxane (A) has absorption for the CO2 laser, it is possible to form a riblet structure even if an inorganic filler that absorbs at the laser wavelength is not included. From the above viewpoint, the content of inorganic fillers other than titanium dioxide is preferably 1 to 30 parts by mass, more preferably 3 parts by mass or more, even more preferably 5 parts by mass or more, even more preferably 8 parts by mass or more, and even more preferably 12 parts by mass or more, per 100 parts by mass of curable organopolysiloxane (A). Furthermore, the titanium dioxide content is preferably 15 parts by mass or less, more preferably 10 parts by mass or less, even more preferably 5 parts by mass or less, even more preferably 3 parts by mass or less, even more preferably 1 part by mass or less, and even more preferably not contained, per 100 parts by mass of curable organopolysiloxane (A). If the titanium dioxide content is high, the ability to form riblet structures on the coating film by laser irradiation tends to be poor, especially when an IR laser is used as the laser.

[0048] As an inorganic filler other than silica, pigments containing components derived from Fe are preferred. The Fe content in the inorganic filler is measured using an elemental analyzer (Supermini200, manufactured by Rigaku Corporation), and those with an Fe content exceeding 10% are considered to contain components derived from Fe. In the antifouling coating composition, the content of the pigment containing Fe-derived components is preferably 1 to 30 parts by mass, more preferably 3 parts by mass or more, even more preferably 5 parts by mass or more, and even more preferably 24 parts by mass or less, and even more preferably 18 parts by mass or less, per 100 parts by mass of curable organopolysiloxane (A), from the viewpoint of facilitating the formation of riblet structures on the coating film by laser irradiation, facilitating the formation of finer riblet structures, and maintaining the antifouling properties of the coating film in which riblet structures have been formed by laser irradiation. As for the pigment containing Fe-derived components, iron oxide is preferred, more preferably at least one selected from the group consisting of yellow iron oxide, red iron oxide, and black iron oxide, and even more preferably at least one selected from the group consisting of yellow iron oxide and red iron oxide. The total content of yellow iron oxide, red iron oxide, and black iron oxide is preferably 1 to 30 parts by mass, more preferably 3 parts by mass or more, even more preferably 5 parts by mass or more, and even more preferably 24 parts by mass or less, and even more preferably 18 parts by mass or less, per 100 parts by mass of curable organopolysiloxane (A).

[0049] In this embodiment, the antifouling coating composition preferably contains a small amount of coarse particles from the viewpoint of obtaining a fine riblet structure. The detection frequency of particles with a particle diameter of 20 μm or more in the total number of particles contained in the antifouling coating composition of this embodiment is preferably 10% or less, more preferably 3% or less, and even more preferably 1% or less. The coarse particles mentioned above may be inorganic fillers (C), biological repellents (F) described later, or organic coloring pigments (I), and are not particularly limited. The particles contained in the antifouling coating composition are particles that can be detected by the method described in the examples. The detection frequency of particles with a particle diameter of 20 μm or more in the total number of particles contained in the antifouling coating composition is measured by the method described in the examples, or it may be calculated from the particle size distribution formed by a laser diffraction particle size distribution analyzer after diluting the antifouling coating composition with a solvent such as xylene as needed (preferably the solvent contained in the antifouling coating composition) as required. Furthermore, "detection frequency" means the cumulative frequency of the volume fraction within a specific particle size range. Similarly, the detection frequency of particles with a particle diameter of 10 μm or more among the total particles contained in the antifouling coating composition of this embodiment is preferably 20% or less, more preferably 5% or less, and even more preferably 2% or less, while the detection frequency of particles with a particle diameter of 5 μm or more is preferably 70% or less, and more preferably 50% or less.

[0050] <Slip agent (D)> The antifouling coating composition of this embodiment preferably contains a slip agent (D) from the viewpoint of improving its antifouling properties against aquatic organisms. The slip agent (D) is liquid at 23°C and is not particularly limited as long as it imparts slipperiness to the antifouling coating, thereby inhibiting the adhesion of aquatic organisms to the antifouling coating. When the antifouling coating composition of this embodiment contains the slip agent (D), it also has the effect of improving workability when forming the coating. Such a slip agent (D) preferably contains one or more selected from the group consisting of silicone oil (D1) and polymers (D2) containing constituent units derived from hydrophilic group-containing unsaturated monomers, from the viewpoint of the antifouling properties of the antifouling coating and the workability when forming the coating. More preferably, it contains at least silicone oil (D1) from the viewpoint of facilitating the formation of a riblet structure on the coating by laser irradiation. These slip agents (D) may be used individually or in combination of two or more types.

[0051] When the antifouling coating composition of this embodiment contains a slip agent (D), the total content thereof is preferably 5 to 120 parts by mass, more preferably 8 parts by mass or more, even more preferably 12 parts by mass or more, more preferably 100 parts by mass or less, even more preferably 80 parts by mass or less, even more preferably 70 parts by mass or less, and even more preferably 60 parts by mass or less, from the viewpoint of improving antifouling properties against aquatic organisms, improving paintability, maintaining the antifouling properties of the coating film in which a riblet structure has been formed by laser irradiation, and facilitating the formation of a riblet structure on the coating film by laser irradiation, per 100 parts by mass of curable organopolysiloxane (A). Furthermore, from a similar viewpoint, the total content of the slip agent (D) in the solid content of the antifouling coating composition is preferably 3% by mass or more and 80% by mass or less, more preferably 5% by mass or more, even more preferably 7% by mass or more, and more preferably 60% by mass or less, even more preferably 40% by mass or less, and even more preferably 30% by mass or less.

[0052] [Silicone oil (D1)] The silicone oil (D1) is an oil containing a polyorganosiloxane in the polymer main chain, and a silicone oil represented by the following formula (D1) is preferred.

[0053] [ka]

[0054] In formula (D1), R 31 and R 32 Each independently represents a C1-C50 alkyl group, alkenyl group, aryl group, aralkyl group, or halogenated alkyl group which may contain a hydrogen atom or a group having a heteroatom in its structure, and R 33 represents a divalent hydrocarbon group having 1 to 50 carbon atoms, which may have a single bond or a group containing a heteroatom. s represents an integer between 10 and 1,000.

[0055] R 31 and R 32 When the group represents an alkyl group, alkenyl group, aryl group, aralkyl group, or halogenated alkyl group having 1 to 50 carbon atoms, each of these groups may independently contain a group having a heteroatom in its structure. Examples of heteroatoms include oxygen atoms, nitrogen atoms, and sulfur atoms. Furthermore, examples of heteroatom-containing groups include ether groups, thioether groups, ester groups, amino groups, amide groups, hydroxyl groups, carboxyl groups, and thiol groups. The presence of a heteroatom-containing group in the structure means, for example, in the case of an alkyl group, that the structure has a heteroatom-containing group interposed between the carbon-carbon bonds of the alkyl group, or that the hydrogen atoms of the alkyl group are substituted with a heteroatom-containing group. The heteroatom-containing group may be one type or two or more types, and if there are multiple heteroatom-containing groups, they may be the same or different. Multiple Rs exist 31 and R 32 These may be the same or different.

[0056] As for silicone oil (D1), R 31 and R 32 It is preferable that the group is composed solely of alkyl groups, or of alkyl groups and aryl groups. R 31 and R 32 There are several types of silicone oils (D1) that consist only of alkyl groups. 31 and R 32 However, those composed entirely of methyl groups, and those composed of methyl groups and alkyl groups other than methyl groups are preferred, and those composed entirely of methyl groups, and those composed of alkyl groups having methyl groups and ether groups are more preferred. From then on, R 31 and R 32 However, silicone oil (D1) composed entirely of methyl groups is called "polydimethylsiloxane (unmodified)".

[0057] Examples of alkyl groups having an ether group include those having the following chemical structure. -R 34 (C2H4O) a (C3H6O) b R 35 (Here, R 34 R represents an alkylene group with 1 to 20 carbon atoms. 35 (where represents an alkyl group having 1 to 20 carbon atoms, a and b each independently represent integers from 0 to 30, and a+b is an integer greater than or equal to 1.) From then on, R 31 and R 32 A silicone oil (D1) composed of alkyl groups having methyl and ether groups is called "ether-modified polydimethylsiloxane".

[0058] The aforementioned R 31 and R 32 As a silicone oil (D1) composed of alkyl and aryl groups, R 31 and R 32Preferably, it is composed of a methyl group and a phenyl group, and all R 31 and R 32 A higher percentage of phenyl groups (phenyl denaturation rate) is preferred, with a ratio of 3% to 50%. From then on, R 31 and R 32 A silicone oil (D1) composed of methyl and phenyl groups is called "phenyl-modified polydimethylsiloxane".

[0059] In formula (D1), R 33 This represents a divalent hydrocarbon group having 1 to 50 carbon atoms, which may have a single bond or a group containing a heteroatom. Examples of groups containing a heteroatom include -NR a - represents the group (R a (where is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms), ether group, thioether group (-S-), ester group (-C(=O)-O-), and amide group (-C(=O)-NR b -, R b Examples include a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. 33 The heteroatom-containing groups in the compound may consist of one type or two or more types, and if there are multiple heteroatom-containing groups, they may be the same or different.

[0060] In the above formula (D1), R 33 Examples of divalent hydrocarbon groups having 1 to 50 carbon atoms include linear or branched alkylene groups having 1 to 50 carbon atoms. Examples of linear alkylene groups include methylene, ethylene, trimethylene, tetramethylene, hexamethylene, octamethylene, decamethylene, dodecamethylene, tetradecamethylene, hexadecamethylene, octadecamethylene, and eicosalene groups. Examples of branched alkylene groups include propylene, isopropylene, isobutylene, 2-methyltrimethylene, isopentethylene, isohexylene, isooctylene, 2-ethylhexylene, and isodecylene groups. Multiple Rs exist 33 These may be the same or different.

[0061] R 33 A single bond is preferred. 33 However, in the case of a divalent hydrocarbon group having 1 to 50 carbon atoms with an ether group interposed therein, examples include those having the following chemical structure. -R 36 (C2H4O) a (C3H6O) b R 37 - (R 36 and R 37 Each of the following independently represents an alkylene group having 1 to 10 carbon atoms, a and b independently represent integers from 0 to 30, and a+b is an integer greater than or equal to 1. In this invention, unless otherwise specified, "hydrocarbon group" means a group consisting only of carbon and hydrogen, and includes saturated or unsaturated linear and branched aliphatic groups, alicyclic groups, and aromatic groups.

[0062] The viscosity of the silicone oil (D1) at 23°C is preferably 10 mPa·s or more, more preferably 20 mPa·s or more, even more preferably 40 mPa·s or more, even more preferably 60 mPa·s or more, even more preferably 80 mPa·s or more, and preferably 10,000 mPa·s or less, more preferably 5,000 mPa·s or less, and even more preferably 3,000 mPa·s or less, from the viewpoint of improving workability during the manufacture of the antifouling paint composition, the paintability, curability of the antifouling paint composition, and the strength and flexibility of the formed coating film. In this specification, the viscosity of silicone oil (D1) at 23°C refers to the viscosity measured using a Type B rotational viscometer.

[0063] The antifouling paint composition of this embodiment preferably contains, as the silicone oil (D1), one or more selected from the group consisting of ether-modified polydimethylsiloxane and phenyl-modified polydimethylsiloxane from the viewpoints of improving workability during film formation, ease of forming a riblet structure on the coating film by laser irradiation, etc., and more preferably contains phenyl-modified polydimethylsiloxane. Such silicone (D1) may be contained alone or in combination of two or more. When the antifouling paint composition of this embodiment contains silicone oil (D1), the content of silicone oil (D1) in the solid content of the antifouling paint composition is preferably 0.1% by mass or more, more preferably 1% by mass or more, still more preferably 3% by mass or more, even more preferably 5% by mass or more, still more preferably 7% by mass or more, and preferably 50% by mass or less, more preferably 40% by mass or less, still more preferably 30% by mass or less, from the viewpoints of improving the antifouling property of the antifouling coating film, maintaining the antifouling property of the coating film having a riblet structure formed by laser irradiation, and improving workability during film formation.

[0064] Commercially available silicone oil (D1) can be used. Examples of commercially available products include, for example, "KF-96-1,000cs" (manufactured by Shin-Etsu Chemical Co., Ltd., kinematic viscosity (25 °C): 1,000 mm 2 / s) as the above-mentioned polydimethylsiloxane (unmodified), "KF-50-1,000cs" (manufactured by Shin-Etsu Chemical Co., Ltd., phenyl modification rate = 5%, kinematic viscosity (25 °C): 1,000 mm 2 / s), "KF-50-100cs" (manufactured by Shin-Etsu Chemical Co., Ltd., phenyl modification rate = 5%, kinematic viscosity (25 °C): 100 mm 2 / s) as the above-mentioned phenyl-modified polydimethylsiloxane, "X-22-4272" (manufactured by Shin-Etsu Chemical Co., Ltd., the above-mentioned R 31 a part of which is an alkyl group having an ether group, ether-modified polydimethylsiloxane, kinematic viscosity (25 °C): 270 mm 2 / s), "KF-6020" (manufactured by Shin-Etsu Chemical Co., Ltd., the above-mentioned R 32Part of it is an ether-modified polydimethylsiloxane having an alkyl group with an ether group, kinematic viscosity (25 ° C): 180 mm 2 / s), "FZ-2203" (manufactured by Toray Dow Corning Co., Ltd., where the R 33 Part of it is a polydimethylsiloxane having an alkylene group with an ether group), "FZ-2160" (manufactured by Toray Dow Corning Co., Ltd., where the R 33 Part of it is a polydimethylsiloxane having a propylene group with an ether group), etc. may be mentioned.

[0065] [Polymer (D2) containing a structural unit derived from a hydrophilic group-containing unsaturated monomer] The polymer (D2) containing a structural unit derived from a hydrophilic group-containing unsaturated monomer (hereinafter also referred to as polymer (D2)) is an unsaturated monomer (d21) represented by the following formula (I), tetrahydrofurfuryl (meth)acrylate (d22), 4-(meth)acryloylmorpholine (d23) and vinylpyrrolidone (d24). It preferably contains a polymer (D2) having a structural unit derived from one or more hydrophilic group-containing unsaturated monomers selected from the group consisting of Among these, when the antifouling coating film of the present invention contains the polymer (D2), containing a polymer (D2) having a structural unit derived from the unsaturated monomer (d21) represented by the following formula (I) is from the viewpoint of improving the antifouling property of the antifouling coating film, the ease of forming the antifouling coating film, and the interlayer adhesion with the base material layer, the undercoat layer, etc., and preventing the coating film manufacturing apparatus from being contaminated by the antifouling coating composition during coating. etc. is preferable.

[0066] [Chemical formula]

[0067] In formula (I), R 1 represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, and R 2 represents an ethylene group or a propylene group, and R 3 represents a divalent hydrocarbon group having 4 to 10 carbon atoms, and R 4represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 30 carbon atoms, m represents an integer from 1 to 50, n represents an integer from 0 to 50, and X 1 This indicates an ester bond, an amide bond, or a single bond.

[0068] R 1 R represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. Examples of such monovalent hydrocarbon groups include alkyl groups such as methyl and ethyl groups; alkenyl groups such as vinyl and propenyl groups; aryl groups such as phenyl groups; and aralkyl groups such as benzyl groups, with alkyl groups being preferred. 1 The number of carbon atoms in the monovalent hydrocarbon group in is preferably 1 to 6, more preferably 1 to 4, even more preferably 1 or 2, and particularly preferably 1 (i.e., the monovalent hydrocarbon group is a methyl group). 1 A hydrogen atom or an alkyl group is preferred, a hydrogen atom or a methyl group is more preferred, and a hydrogen atom is even more preferred.

[0069] R 2 R represents an ethylene group or a propylene group. If m is an integer of 2 or more, there are multiple R groups. 2 These may be the same or different. Furthermore, when m is 2 or greater, it is preferable that it has at least one ethylene group. 2 It is more preferable that it be an ethylene group.

[0070] R 3 R represents a divalent hydrocarbon group having 4 to 10 carbon atoms. Examples of such divalent hydrocarbon groups include linear or branched alkylene groups such as butylene; alkenylene; and arylene groups such as phenylene. Among these, R 3 Linear or branched alkylene groups are preferred, butylene groups are more preferred, and n-butylene groups are even more preferred. Note that if n is an integer of 2 or more, there are multiple R groups. 3 They may be the same or different.

[0071] R in equation (I) 4R represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 30 carbon atoms. Examples of such monovalent hydrocarbon groups include linear, branched, or cyclic saturated or unsaturated aliphatic hydrocarbon groups and aromatic hydrocarbon groups, more specifically, methyl, ethyl, propyl, butyl, hexyl, cyclohexyl, phenyl, octyl, dodecyl, octadecyl, nonylphenyl, etc. 4 Preferably, is a hydrogen atom or an aliphatic hydrocarbon, more preferably a hydrogen atom or a methyl group, and even more preferably a methyl group. R 4 With such substituents, the polymer (D2) exhibits desirable hydrophilicity, and the formed antifouling coating can be given excellent antifouling properties. 4 If the group has heteroatoms other than hydrogen and carbon atoms, the antifouling properties may be reduced.

[0072] In equation (I), m is an integer between 1 and 50, preferably between 1 and 15. In equation (I), n is an integer between 0 and 50, preferably between 0 and 20, and more preferably 0. In this specification, when two or more different repeating units are listed in parallel between brackets [ ], it indicates that these repeating units may be repeated in any form and order, whether random, alternating, or block-like. That is, for example, in formula -[X3-Y3]- (where X and Y represent repeating units), the repeating units may be in a random form such as -XXYXYY-, an alternating form such as -XYXYXY-, or a block-like form such as -XXXYYY- or -YYYXXX-.

[0073] In equation (I), X 1 This represents an ester bond (-C(=O)O-), an amide bond (-C(=O)NH-), or a single bond, preferably an ester bond (-C(=O)O-). Note X 1 If the bond is an ester bond or an amide bond, the carbonyl carbon is R 1 It is preferable that it bonds with a carbon atom to which it is bonded.

[0074] The unsaturated monomer (d21) represented by formula (I) is preferably a compound represented by the following formula (II) from the viewpoint of availability, cost-effectiveness, etc.

[0075] [ka]

[0076] In formula (II), R 1’ R represents a hydrogen atom or a methyl group. 2 represents an ethylene group or a propylene group, m represents an integer from 1 to 50, and R 4’ represents a hydrogen atom or a methyl group.

[0077] In formula (II), R 1’ It is preferably a hydrogen atom, which represents either a hydrogen atom or a methyl group. R 2 R represents an ethylene group or a propylene group. Note that if m is an integer of 2 or more, there may be multiple R groups. 2 These may be the same or different, R 2 At least one of them is preferably an ethylene group. 2 It is more preferable that it be an ethylene group. m represents an integer between 1 and 50, preferably between 1 and 15, more preferably between 2 and 14, and even more preferably between 3 and 13. R 4’ represents a hydrogen atom or a methyl group. When m is 1, R 4’ It is preferably a hydrogen atom or a methyl group, and when m is an integer of 2 or more, it is preferably a methyl group.

[0078] The unsaturated monomer (d21) is more preferably a compound represented by the following formula (III).

[0079] [ka]

[0080] In formula (III), R 1’ , and m are R in formula (II) above. 1’ It is the same as m.

[0081] Examples of such unsaturated monomers (d21) include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 2-methoxypropyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, poly(ethylene glycol-propylene glycol) mono(meth)acrylate, poly(ethylene glycol-butylene glycol) mono(meth)acrylate, methoxypolyethylene glycol mono(meth)acrylate, allyloxypoly(ethylene glycol-propylene glycol) mono(meth)acrylate, phenoxypolyethylene glycol-polypropylene glycol methacrylate, octoxypoly(ethylene glycol-propylene glycol) mono(meth)acrylate, dodecyloxypolyethylene glycol mono(meth)acrylate, octadecyloxypolyethylene glycol mono(meth)acrylate, nonylphenoxypolypropylene glycol acrylate, and ethylene glycol monoallyl ether. Among these, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 2-methoxypropyl (meth)acrylate, and methoxypolyethylene glycol mono(meth)acrylate are preferred, more preferably 2-methoxyethyl (meth)acrylate, 2-methoxypropyl (meth)acrylate, and methoxypolyethylene glycol mono(meth)acrylate are preferred, and even more preferably 2-methoxyethyl (meth)acrylate and methoxypolyethylene glycol mono(meth)acrylate are preferred. In this specification, "(meth)acrylate" means "acrylate or methacrylate," and other similar terms have the same meaning.

[0082] Commercially available unsaturated monomers (d21) can be used, for example, NK ester AM-90G (methoxypolyethylene glycol #400 acrylate), NK ester AM-130G (methoxypolyethylene glycol #550 acrylate), NK ester M-90G (methoxypolyethylene glycol #400 methacrylate), and NK ester manufactured by Shin Nakamura Chemical Industry Co., Ltd. M-230G (Methoxypolyethylene glycol #1000 methacrylate); Light acrylate MTG-A (Methoxy-triethylene glycol acrylate), Light acrylate EC-A (Ethoxy-diethylene glycol acrylate), Light acrylate EHDG-AT (2-Ethylhexyl-diethylene glycol acrylate), Light ester HOA(N) (2-Hydroxyethyl acrylate), Light ester HO-250(N) (2-Hydroxyethyl methacrylate), Light ester HOP(N) (2-Hydroxypropyl methacrylate), Light ester 041MA (Methoxypolyethylene glycol methacrylate); manufactured by NOF Corporation. Examples include Lemmer ANP-300 (nonylphenoxy polypropylene glycol acrylate), Bremmer AP-400 (polypropylene glycol monoacrylate), Bremmer 70PEP-350B (polyethylene glycol polypropylene glycol monomethacrylate), Bremmer 55PET-800 (polyethylene glycol tetramethylene glycol monomethacrylate), Bremmer 50POEP-800B (octoxy polyethylene glycol polypropylene glycol methacrylate); SR504 (ethoxylated nonylphenyl acrylate) from Arkema Inc.; and Viscoat #MTG (methoxy polyethylene glycol acrylate) from Osaka Organic Chemical Industry Co., Ltd.

[0083] The tetrahydrofurfuryl (meth)acrylate (d22) can be used without limitation as long as it has a tetrahydrofurfuryl (meth)acrylate structure. That is, the tetrahydrofurfuryl (meth)acrylate (d22) may be a compound having one or more arbitrary substituents on the oxolane ring of the tetrafurfuryl (meth)acrylate. Examples of such substituents include C1-C6 alkyl groups, C1-C6 halogenated alkyl groups, C6-C14 aryl groups, C1-C7 acyl groups, halogen atoms, hydroxyl groups, and the like. As the tetrahydrofurfuryl (meth)acrylate (d22), tetrahydrofurfuryl acrylate and tetrahydrofurfuryl methacrylate are preferred, with tetrahydrofurfuryl acrylate being more preferred.

[0084] The 4-(meth)acryloylmorpholine (d23) can be used without limitation as long as it has a 4-(meth)acryloylmorpholine structure. That is, 4-(meth)acryloylmorpholine (d23) may be a compound having one or more arbitrary substituents on the morpholine ring of 4-(meth)acryloylmorpholine. Examples of such substituents include C1-C6 alkyl groups, C1-C6 halogenated alkyl groups, C6-C14 aryl groups, C1-C7 acyl groups, halogen atoms, and hydroxyl groups. As 4-(meth)acryloylmorpholine (d23), 4-acryloylmorpholine and 4-methacryloylmorpholine are preferred, and 4-acryloylmorpholine is more preferred.

[0085] The vinylpyrrolidone (d24) can be any compound having a vinylpyrrolidone structure and can be used without limitation. That is, it may be a compound having one or more arbitrary substituents on the pyrrolidine ring. Examples of such substituents include C1-C6 alkyl groups, C1-C6 halogenated alkyl groups, C6-C14 aryl groups, C1-C7 acyl groups, halogen atoms, and hydroxyl groups. Examples of vinylpyrrolidone (d24) include 1-vinyl-2-pyrrolidone, 3-acetyl-1-vinylpyrrolidine-2-one, and 3-benzoyl-1-vinylpyrrolidine-2-one. Among these, 1-vinyl-2-pyrrolidone (also called N-vinyl-2-pyrrolidone) is preferred as vinylpyrrolidone (d24).

[0086] The content of constituent units in the polymer (D2) that are derived from one or more selected from the group consisting of the unsaturated monomer (d21) represented by formula (I), tetrahydrofurfuryl (meth)acrylate (d22), 4-(meth)acryloylmorpholine (d23), and vinylpyrrolidone (d24) is preferably 1% by mass or more and 100% by mass or less, more preferably 3% by mass or more, even more preferably 5% by mass or more, even more preferably 10% by mass or more, and even more preferably 80% by mass or less, even more preferably 70% by mass or less, and even more preferably 50% by mass or less. Furthermore, the ratio of the content (mass) of constituent units in polymer (D2) that are selected from the group consisting of unsaturated monomer (d21), tetrahydrofurfuryl (meth)acrylate (d22), 4-(meth)acryloylmorpholine (d23), and vinylpyrrolidone (d24) can be considered to be the same as the ratio of the amounts (mass) of the monomers (d21) to (d24) used in the polymerization reaction.

[0087] In the present invention, polymer (D2) may be a homopolymer having a constituent unit derived from one unsaturated monomer selected from the group consisting of unsaturated monomer (d21), tetrahydrofurfuryl (meth)acrylate (d22), 4-(meth)acryloylmorpholine (d23), and vinylpyrrolidone (d24), or it may be a copolymer having a constituent unit derived from two or more unsaturated monomers selected from the group consisting of unsaturated monomer (d21), tetrahydrofurfuryl (meth)acrylate (d22), 4-(meth)acryloylmorpholine (d23), and vinylpyrrolidone (d24). In the present invention, it is preferable that the polymer (D2) is a copolymer having constituent units derived from one or more unsaturated monomers selected from the group consisting of unsaturated monomers (d21), tetrahydrofurfuryl (meth)acrylate (d22), 4-(meth)acryloylmorpholine (d23), and vinylpyrrolidone (d24), and further, if necessary, constituent units derived from one or more other unsaturated monomers (d25). As other unsaturated monomers (d25), it is preferable to include the unsaturated monomer (d25-1) represented by the following formula (IV).

[0088] [ka]

[0089] In the above equation (IV), R 41 R represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. 42 X represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 50 carbon atoms. 2 This indicates an ester bond, an amide bond, or a single bond.

[0090] In equation (IV), R 41 R represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. The monovalent hydrocarbon group is R in formula (I) above. 1 Similar groups can be cited, preferably a hydrogen atom or an alkyl group, more preferably a hydrogen atom or a methyl group, and even more preferably a hydrogen atom.

[0091] In equation (IV), R 42The symbol represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 50 carbon atoms, preferably 1 to 30 carbon atoms. Examples of such monovalent hydrocarbon groups include linear or branched hydrocarbon groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, sec-butyl, n-pentyl, n-hexyl, n-octyl, isooctyl, 2-ethylhexyl, dodecyl, and octadecyl groups; and cyclic hydrocarbon groups such as cyclohexyl, phenyl, and benzyl groups; with n-butyl, isobutyl, and 2-ethylhexyl groups being preferred.

[0092] In equation (IV), X 2 The bond represents an ester bond (-C(=O)O-), an amide bond (-C(=O)NH-), or a single bond, and among these, an ester bond is preferred. Note X 2 When it is an ester bond or an amide bond, the carbonyl carbon is R 41 It is preferable that it bonds with a carbon atom to which it is bonded.

[0093] Examples of such unsaturated monomers (d25-1) include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, n-pentyl (meth)acrylate, hexyl (meth)acrylate, cyclohexyl (meth)acrylate, n-octyl (meth)acrylate, and isooctyl (meth)acrylate. Examples include 2-ethylhexyl (meth)acrylate, 3,5,5-trimethylhexyl (meth)acrylate, lauryl (meth)acrylate, cetyl (meth)acrylate, stearyl (meth)acrylate, isostearyl (meth)acrylate, phenyl (meth)acrylate, and benzyl (meth)acrylate, among these, n-butyl (meth)acrylate, isobutyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate are preferred.

[0094] It is also preferable to include an organopolysiloxane group-containing unsaturated monomer (d25-2) as another unsaturated monomer (d25). Commercially available organopolysiloxane group-containing unsaturated monomers (d25-2) can be used, such as Cyraprene TM-0701T (tris(trimethylsiloxy)silylpropyl methacrylate), Cyraprene FM-0711 (methacrylic group-containing dimethylpolysiloxane, number average molecular weight 1,000), and Cyraprene FM-0721 (methacrylic group-containing dimethylpolysiloxane, number average molecular weight 5,000), all manufactured by JNC Corporation. Including an organopolysiloxane group-containing unsaturated monomer (d25-2) as another unsaturated monomer (d25) can improve the antifouling properties of the formed antifouling coating. However, it may reduce the adhesion of the coating to the substrate in some cases, so it is necessary to adjust the composition appropriately depending on the type of substrate on which the antifouling coating is formed.

[0095] If the polymer (D2) contains constituent units derived from other monomers (d25), the content of these constituent units in the polymer (D2) is preferably 99% by mass or less, more preferably 97% by mass or less, even more preferably 95% by mass or less, and even more preferably 90% by mass or less, and also preferably 20% by mass or more, more preferably 30% by mass or more, and even more preferably 50% by mass or more.

[0096] In the present invention, the weight-average molecular weight (Mw) of the polymer (D2) is preferably 1,000 or more, more preferably 3,000 or more, even more preferably 5,000 or more, particularly preferably 7,000 or more, and preferably 150,000 or less, more preferably 100,000 or less, even more preferably 50,000 or less, particularly preferably 30,000 or less, from the viewpoint of the antifouling properties of the antifouling coating film formed and the viscosity of the antifouling coating composition. When the weight-average molecular weight (Mw) of the polymer (D2) is within the above range, it is preferable in terms of providing good antifouling properties to the formed coating film and facilitating the formation of an antifouling coating film.

[0097] In this embodiment, from the viewpoint of ease of forming a riblet structure by laser irradiation, the content of polymer (D2) in the antifouling coating composition is preferably 10 parts by mass or less, more preferably 8 parts by mass or less, even more preferably 5 parts by mass or less, even more preferably 3 parts by mass or less, even more preferably 1 part by mass or less, and even more preferably not present, per 100 parts by mass of curable organopolysiloxane (A). It is preferable that the polymer (D2) content is within the above range because a finer riblet structure is formed. Furthermore, from the viewpoint of antifouling properties, it is preferable that the antifouling coating composition contains polymer (D2), and the content of polymer (D2) in the antifouling coating composition is preferably 0.5 parts by mass or more, more preferably 1.0 part by mass or more, even more preferably 2.0 parts by mass or more, and even more preferably 3.0 parts by mass or more, per 100 parts by mass of curable organopolysiloxane (A). In the present invention, the polymer (D2) may be used alone or in combination of two or more types.

[0098] <Silane coupling agent (E)> The antifouling coating composition of this embodiment may contain a silane coupling agent (E) other than the organosilicon crosslinking agent (B) described above, for the purpose of improving interlayer adhesion with the substrate layer and the undercoat layer. As the silane coupling agent (E), it is preferable to use a compound represented by the following formula (E1).

[0099] [ka]

[0100] In formula (E1), R 21 and R 22 Each of these independently represents a monovalent hydrocarbon group having 1 to 10 carbon atoms, and R 23 represents a divalent hydrocarbon group having 1 to 20 carbon atoms, which may have a heteroatom interposed therein; Z represents a polar group; and w represents an integer of 2 or 3.

[0101] In the above equation (E1), R 21 and R22 Each of these independently represents a monovalent hydrocarbon group having 1 to 10 carbon atoms. 21 Examples of monovalent hydrocarbon groups having 1 to 10 carbon atoms in R include alkyl groups having 1 to 10 carbon atoms. 22 Examples of monovalent hydrocarbon groups having 1 to 10 carbon atoms include alkyl groups having 1 to 10 carbon atoms, alkenyl groups having 2 to 10 carbon atoms, and aryl groups having 6 to 10 carbon atoms. R 21 and R 22 Alkyl groups with 1 to 10 carbon atoms in R 22 The alkenyl group having 2 to 10 carbon atoms and the aryl group having 6 to 10 carbon atoms in formula (A1) are R 11 and R 13 Among the examples given, those with the corresponding number of carbon atoms can be similarly listed.

[0102] In the above equation (E1), R 21 Preferably, the alkyl group has 1 to 10 carbon atoms, more preferably a methyl group, an ethyl group, a propyl group, and a butyl group, and even more preferably a methyl group. Multiple Rs exist 21 These may be the same or different.

[0103] In the above equation (E1), R 22 Preferably, the group is an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, and an aryl group having 6 to 10 carbon atoms; more preferably, a methyl group, an ethyl group, a propyl group, a butyl group, and a phenyl group; even more preferably, a methyl group; and still more preferably, a methyl group.

[0104] In the above equation (E1), R 23 R represents a divalent hydrocarbon group having 1 to 20 carbon atoms, which may have a heteroatom interposed therein. 23 As for the divalent hydrocarbon group having 1 to 20 carbon atoms in the above formula (C1), R 33 Among those exemplified above, those with the corresponding number of carbon atoms can be similarly listed. Of these, alkylene groups with 4 to 11 carbon atoms are preferred.

[0105] As a group having a heteroatom, R in formula (D1) is 33 The examples given above are similar. Among these, -NR a - A - group is preferred, and an -NH- group is more preferred. 23 The heteroatom-containing groups in the compound may consist of one type or two or more types, and if there are multiple heteroatom-containing groups, they may be the same or different.

[0106] In the above formula (E1), Z represents a polar group. Preferably, the polar group is an amino group or an iminoalkyl group (-CR c =NH, R c The group is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms), a glycidoxy group, an isocyanate group, a thiol group, a hydrosilyl group, and a (meth)acryloyloxy group, more preferably an amino group. The amino group in Z of the above formula (E1) may be a primary amino group, a secondary amino group, or a tertiary amino group, with a primary amino group being preferred. In formula (E1), w is an integer of 2 or 3, preferably 3.

[0107] Examples of such silane coupling agents (E) include 3-(2-aminoethylamino)propyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-(2-(2-aminoethylamino)ethylamino)propyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-isocyanatepropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, and N-phenyl-3-aminopropyltrimethoxysilane. As the silane coupling agent (E), a partial condensate of the compound represented by the above formula (E1) may be used. The silane coupling agent (E) may be used alone or in combination of two or more types.

[0108] When the antifouling coating composition of this embodiment contains a silane coupling agent (E), the content of the silane coupling agent (E) in the solid content of the antifouling coating composition is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, even more preferably 0.10% by mass or more, and preferably 10% by mass or less, more preferably 2% by mass or less, and even more preferably 0.5% by mass or less, from the viewpoint of improving interlayer adhesion with the substrate layer and the undercoat layer. Furthermore, when the antifouling coating composition of this embodiment contains a silane coupling agent (E), the amount of silane coupling agent (E) per 100 parts by mass of curable organopolysiloxane (A) is preferably 0.03 parts by mass or more, more preferably 0.10 parts by mass or more, even more preferably 0.20 parts by mass or more, and preferably 20 parts by mass or less, more preferably 5 parts by mass or less, even more preferably 1 part by mass or less, and even more preferably 0.3 parts by mass or less.

[0109] <Biological repellent (F)> The antifouling coating composition of this embodiment may contain a biological repellent (F) for the purpose of enhancing the antifouling properties of the antifouling coating film formed, and it is preferable that it contains one. The biological repellent (F) is released from the antifouling coating in water and has the effect of suppressing the adhesion of aquatic organisms to the surface of the antifouling coating, thereby improving its antifouling properties. The biological repellent (F) has a repellent effect on aquatic organisms and has a constant elution rate into water, and is composed of copper pyrithione, zinc pyrithione, 4-bromo-2-(4-chlorophenyl)-5-(trifluoromethyl)-1H-pyrrole-3-carbonitrile (also known as tralopyril), 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one (also known as DCOIT), cuprous oxide, copper rhodane, copper, pyrithione salts other than copper pyrithione and zinc pyrithione, borane-nitrogen-based base adducts (pyridinetriphenylborane, 4-isopropylpyridinediphenylmethylborane, etc.), (+ / -)-4-[1-(2,3-dimethylphenyl)ethyl]-1H-imidazole (also known as medetomidine), N,N-dimethyl-N'-(3,4-dichloro Examples include phenyl)urea, N-(2,4,6-trichlorophenyl)maleimide, 2-methylthio-4-tert-butylamino-6-cyclopropylamino-1,3,5-triazine, 2,4,5,6-tetrachloroisophthalonitrile, bisdimethyldithiocarbamoylzinc ethylenebisdithiocarbamate, chloromethyl-n-octyl disulfide, N,N-dimethyl-N'-phenyl-(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, from the viewpoint of excellent elution from the formed antifouling coating film, excellent antifouling properties, antifouling properties against a wide range of biological species, ease of forming the antifouling coating film, improvement of the strength and flexibility of the antifouling coating film, and ease of forming a riblet structure on the coating film by laser irradiation, it is preferable to contain one or more selected from the group consisting of copper pyrithione, zinc pyrithione, 4-bromo-2-(4-chlorophenyl)-5-(trifluoromethyl)-1H-pyrrole-3-carbonitriel (also known as tralopyril), and 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one (also known as DCOIT), more preferable to contain one or more selected from the group consisting of copper pyrithione and zinc pyrithione, and even more preferable to contain copper pyrithione from the viewpoint of having an appropriate elution rate. The content ratio of one or more substances selected from the group consisting of copper pyrithione and zinc pyrithione to the total amount of biological repellent (F) is preferably 50% by mass or more, more preferably 80% by mass or more, and even more preferably 95% by mass or more, from the viewpoint of the antifouling properties of the formed antifouling coating film and the ease of forming a riblet structure on the coating film by laser irradiation. The upper limit of the content is not particularly limited, i.e., 100% by mass. These biological repellents (F) may be used individually or in combination of two or more types.

[0110] Furthermore, examples of copper pyrithione include those having a structure in which M is Cu in the following formula (F1), and examples of zinc pyrithione include those having a structure in which M is Zn in the following formula (F1).

[0111] [ka]

[0112] In formula (F1), R independently represents hydrogen, a C1-C6 alkyl group, a C3-C6 cycloalkyl group, a C2-C6 alkenyl group, a phenyl group, a C1-C6 alkoxy group, or a C1-C6 halogenated alkyl group; M represents a metal atom of Na, Mg, Ca, Ba, Fe, or Sr; and n is the valence of the metal atom M.

[0113] The content of the biological repellent (F) in the solid content of the antifouling coating composition of this embodiment is preferably 0.03% by mass or more, more preferably 0.1% by mass or more, even more preferably 0.5% by mass or more, and preferably 30% by mass or less, more preferably 20% by mass or less, and even more preferably 10% by mass or less, from the viewpoint of improving the antifouling properties of the antifouling coating film formed. Furthermore, in the antifouling coating composition of this embodiment, the content of the biological repellent (F) is preferably 0.05% by mass or more, more preferably 0.3% by mass or more, even more preferably 1.0% by mass or more, and preferably 50% by mass or less, more preferably 30% by mass or less, and even more preferably 15% by mass or less, based on 100% by mass of the curable organopolysiloxane (A).

[0114] <Curing catalyst (G)> The antifouling coating composition of this embodiment may contain a curing catalyst (G) for the purpose of improving the curing speed of the formed coating film and improving the strength of the coating film. Examples of the curing catalyst (G) include the curing catalyst described in Japanese Patent Publication No. 4-106156. Specifically, tin carboxylates such as tin naphthenate and tin oleate; Tin compounds such as dibutyltin diacetate, dibutyltin acetoacetonate, dibutyltin dilaurate, dibutyltin diolate, dibutyltin oxide, dibutyltin dimethoxide, dibutyltin dipentanoate, dibutyltin dioctoate, dibutyltin dineodecanoate, dioctyltin dineodecanoate, bis(dibutyltin laurate) oxide, dibutylbis(triethoxysiloxy)tin, bis(dibutyltin acetate) oxide, dibutyltin bis(ethyl maleate), and dioctyltin bis(ethyl maleate); Titanate esters or titanium chelate compounds such as tetraisopropoxytitanium, tetra-N-butoxytitanium, tetrakis(2-ethylhexoxy)titanium, dipropoxybis(acetylacetonato)titanium, and titanium isopropoxyoctyl glycol; Organometallic compounds such as zinc naphthenate, zinc stearate, zinc-2-ethyl octoate, iron-2-ethylhexoate, cobalt-2-ethylhexoate, manganese-2-ethylhexoate, cobalt naphthenate, and alkoxyaluminum compounds; Examples include potassium acetate, sodium acetate, and alkali metal lower fatty acid salts such as lithium oxalate.

[0115] Commercially available curing catalysts (G) can be used. Examples include "NEOSTANN U-100" manufactured by Nitto Chemical Co., Ltd. and "Gleck TL" manufactured by DIC Corporation. The curing catalyst (G) may be used alone or in combination of two or more types. When the antifouling coating composition of this embodiment contains a curing catalyst (G), the content of the curing catalyst (G) in the solid content of the antifouling coating composition is preferably 0.001 to 10% by mass, more preferably 0.01 to 1% by mass, from the viewpoint of improving the curing speed of the formed coating film and balancing it well with the pot life after preparation of the coating composition.

[0116] <Dehydrating agent (H)> The antifouling coating composition of this embodiment may contain a dehydrating agent (H) for the purpose of improving the storage stability of the antifouling coating composition. As the dehydrating agent (H), for example, zeolite known by the general name "molecular sieve," porous alumina, and orthoesters such as alkyl orthoformate, orthoboric acid, isocyanates, etc. can be used. The dehydrating agent (H) may be used alone or in combination of two or more types. When the antifouling coating composition of this embodiment contains a dehydrating agent (H), the content of the dehydrating agent (H) in the solid content of the coating composition is preferably 0.1% by mass or more and 10% by mass or less, more preferably 0.5% by mass or more and 5% by mass or less, from the viewpoint of improving the storage stability of the antifouling coating composition, the ability to prevent skinning of the coating surface (liquid surface) due to moisture, and the manufacturing stability when applying the coating.

[0117] <Organic coloring pigment (I)> The antifouling coating composition of this embodiment may contain organic coloring pigments for the purpose of improving the design and visibility of the antifouling coating film and the coating composition. Examples of organic coloring pigments include naphthol red and phthalocyanine blue. Furthermore, the coloring pigment may also contain various coloring agents such as dyes. Organic coloring pigment (I) may be used alone or in combination of two or more types. When the antifouling coating composition of the present invention contains an organic coloring pigment (I), the content of the organic coloring pigment (I) in the antifouling coating film is preferably 0.05 to 20% by mass, and more preferably 0.1 to 5% by mass.

[0118] <Organic solvent (J)> The antifouling paint composition of this embodiment may contain an organic solvent (J) for the purpose of improving painting workability by keeping the viscosity of the antifouling paint composition low and improving spray atomization. Examples of organic solvents (J) include aromatic hydrocarbon organic solvents, aliphatic hydrocarbon organic solvents, alicyclic hydrocarbon organic solvents, ketone organic solvents, and ester organic solvents, among which aromatic hydrocarbon organic solvents and ketone organic solvents are preferred. Examples of aromatic hydrocarbon organic solvents include toluene, xylene, and mesitylene. Examples of aliphatic hydrocarbon organic solvents include pentane, hexane, heptane, and octane. Examples of alicyclic hydrocarbon organic solvents include cyclohexane, methylcyclohexane, and ethylcyclohexane. Examples of ketone-based organic solvents include acetylacetone, acetone, methyl ethyl ketone, methyl isobutyl ketone, and dimethyl carbonate. Examples of ester-based organic solvents include propylene glycol monomethyl ether acetate. The organic solvent (J) may be used alone or in combination of two or more types. When the antifouling paint composition of this embodiment contains an organic solvent (J), the content of the organic solvent (J) in the antifouling paint composition can be appropriately adjusted according to the viscosity of the paint composition, but is preferably 1% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more, and from the viewpoint of suppressing dripping during painting, is preferably 70% by mass or less, more preferably 40% by mass or less.

[0119] <Slip-preventing agent / settling prevention agent (K)> The antifouling coating composition of this embodiment may contain a sagging prevention agent / settling prevention agent (K). Examples of anti-sagging and anti-settling agents (K) include organic clay waxes (such as stearate salts, lecithin salts, and alkyl sulfonates of Al, Ca, and Zn), organic waxes (such as polyethylene wax, oxidized polyethylene wax, amide wax, polyamide wax, and hydrogenated castor oil wax), and mixtures of organic clay waxes and organic waxes. Commercially available products can be used as anti-sagging and anti-settlement agents (K). Examples of commercially available products include "Disparon 305," "Disparon 4200-20," and "Disparon A630-20X" manufactured by Kusumoto Kasei Co., Ltd. The anti-sagging and anti-settling agents (K) may be used alone or in combination of two or more types. When the antifouling coating composition of this embodiment contains an anti-sagging agent / anti-settling agent (K), the content of the anti-sagging agent / anti-settling agent (K) in the solid content of the antifouling coating composition is preferably 0.01% by mass or more and 10% by mass or less, more preferably 0.1% by mass or more and 3% by mass or less.

[0120] <Enzyme (L)> The antifouling coating composition of this embodiment may contain enzyme (L) for the purpose of improving the antifouling properties of the antifouling coating film that is formed. Examples of enzymes (L) include serine proteases, cysteine ​​proteases, metalloproteinases, cellulases, hemicellulases, pectinases, and glycosidases. Enzyme (L) may be used alone or in combination of two or more types. When the antifouling coating composition of the present invention contains enzyme (L), the enzyme content in the solid content of the antifouling coating composition is preferably 0.0005% by mass or more and 5% by mass or less, more preferably 0.01% by mass or more and 0.1% by mass or less.

[0121] <Flame retardant (M)> The antifouling coating composition of this embodiment may contain a flame retardant (M). Examples of flame retardants (M) include antimony oxide and paraffin oxide. The flame retardant (M) may be used alone or in combination of two or more types. When the antifouling coating composition of this embodiment contains a flame retardant (M), the amount of the flame retardant in the solid content of the antifouling coating composition is preferably 0.01% by mass or more and 20% by mass or less, more preferably 0.1% by mass or more and 1% by mass or less.

[0122] <Heat conduction improver (N)> The antifouling coating composition of this embodiment may contain a thermal conductivity modifier (N). Examples of thermal conductivity modifiers (N) include boron nitride and aluminum oxide. The heat conduction improver (N) may be used alone or in combination of two or more types. When the antifouling coating of the present invention contains a thermal conductivity improver (N), the content of the thermal conductivity improver in the solid content of the antifouling coating composition is preferably 0.01% by mass or more and 20% by mass or less, more preferably 0.1% by mass or more and 1% by mass or less.

[0123] <Aspects of antifouling paint composition> The antifouling coating composition of this embodiment may be a one-component coating consisting of one component, or a multi-component coating consisting of two or more components. When the antifouling coating composition is a multi-component coating, from the viewpoint of ease of preparation of the coating composition, it is preferably two to four components, more preferably two or three components, and even more preferably two components. In the case of a multi-component paint, each component (each liquid) preferably contains one or more components, is individually packaged, and is stored in a container such as a can. The paint composition can be prepared by mixing the contents of each component at the time of painting. Furthermore, when using a multi-component paint, it is preferable that the curable organopolysiloxane (A) and the organosilicon crosslinking agent (B) are contained as separate components.

[0124] [Method for manufacturing an antifouling paint composition] Each of the antifouling coating compositions of this embodiment can be prepared using the same apparatus and means as known general antifouling coatings. Specifically, each component contained in each component can be added all at once or sequentially, then stirred and mixed to produce the composition. Alternatively, the components may be pre-mixed in any combination.

[0125] [Method for manufacturing an antifouling coating] The antifouling coating of the present invention is formed from the antifouling paint composition, and a riblet structure is formed by laser irradiation. The method for manufacturing the antifouling coating of this embodiment preferably comprises the following steps (1) and (2) in this order. Step (1): A step of forming an antifouling coating film on a substrate using the antifouling coating composition of this embodiment. Step (2): A step of irradiating the surface of the antifouling coating with a laser to form a riblet structure.

[0126] In step (1), the antifouling coating composition of this embodiment is applied to a substrate or the like to obtain a coating body, and then the coating body is cured and / or dried to form an antifouling coating film. Methods for applying an antifouling coating composition to form an antifouling coating film include known methods such as spraying, brushing, rolling, using a film applicator, flow coater, or roll coater, as well as impregnating the object to be coated with the antifouling coating composition. The antifouling coating composition applied by the method described above can be dried by leaving it at, for example, 25°C for about 0.5 to 14 days, more preferably 1 to 7 days, to obtain a coating film. The drying of the antifouling coating composition may also be carried out under heating and with a fan.

[0127] In this embodiment, the thickness of the antifouling coating after drying can be arbitrarily selected depending on the renewal rate of the antifouling coating and the period of use, but for example, about 30 to 1,000 μm is preferred. A method for producing a coating of this thickness is to apply the paint composition in one to multiple coats, preferably with a thickness of 10 to 300 μm, more preferably 30 to 200 μm, per application.

[0128] In step (2), the surface of the antifouling coating obtained in step (1) is irradiated with a laser to form a riblet structure. In this specification, a riblet structure refers to a fine, uneven shape with a periodic structure, which, when formed on the surface of an object, has the effect of suppressing the generation of turbulence in the fluid when the fluid comes into contact with the surface of the object. Examples of riblet structures include groove structures as described in Japanese Patent Publication No. 2011-530443 and structures having a specific periodic pattern as described in Japanese Patent Publication No. 2012-508128. From the viewpoint of ease of structure formation, structures having grooves are preferred.

[0129] The riblet structure is characterized by the difference in the height of its irregularities, i.e., the riblet height. In this specification, the riblet height h is defined as the 10-point average line roughness Rzjis (JIS B 0601:2001) of the surface at any cross-section of the riblet-forming surface within any range in which periodic irregularities can be recognized. The riblet height h of the antifouling coating film of the present invention is preferably 0.1 μm to 1000 μm, more preferably 0.5 μm or more, even more preferably 1 μm or more, even more preferably 10 μm or more, even more preferably 15 μm or more, and more preferably 500 μm or less, and even more preferably 100 μm or less, from the viewpoint of suppressing the generation of fluid turbulence and improving fuel efficiency, and from the viewpoint of ease of forming the riblet structure.

[0130] When the riblet structure is a groove structure, examples include V-shaped grooves, U-shaped grooves, rectangular grooves, and trapezoidal grooves. The average distance between the vertices of the irregularities in the longitudinal and perpendicular directions of the groove structure, i.e., the period S [μm] of the groove structure, in relation to the riblet height h, has a ratio of S / h that is preferably 0.5 or more, more preferably 0.8 or more, even more preferably 1.0 or more, and even more preferably 1.1 or more, and preferably 10 or less, more preferably 8 or less, even more preferably 6 or less, and even more preferably 3.5 or less. In particular, in the case of a V-shaped groove and the convex portion is trapezoidal, a longer upper side of the trapezoid in relation to the period S [μm] is desirable from the viewpoint of antifouling properties, and the ratio of (upper side of trapezoid) / S is preferably 0.5 or more, more preferably 0.6 or more, even more preferably 0.8 or more, and even more preferably 0.9 or more.

[0131] From the same viewpoint as above, the riblet structure preferably has a riblet height h of 0.5 μm or more and 500 μm or less and an S / h ratio of 0.5 or more and 10 or less, more preferably a riblet height h of 1 μm or more and 100 μm or less and an S / h ratio of 0.8 or more and 8 or less, even more preferably a riblet height h of 10 μm or more and 100 μm or less and an S / h ratio of 1.0 or more and 6 or less, and even more preferably a riblet height h of 15 μm or more and 100 μm or less and an S / h ratio of 1.1 or more and 3.5 or less.

[0132] In the embodiment, when the riblet structure on the surface of the antifouling coating is a grooved structure and the antifouling coating is used in applications where it is exposed to a dynamic water flow, the longitudinal direction of the riblet grooves with respect to the flow direction of the dynamic water flow may be horizontal or vertical, but horizontal is preferred in that the effect of reducing water flow friction resistance by the riblet structure can be expected.

[0133] The type of laser used to form the riblet structure in step (2) can be appropriately selected from solid-state lasers, semiconductor lasers, gas lasers, and liquid lasers of various wavelengths, and the oscillation mode can also be selected according to the desired surface shape, such as continuous waves or pulsed waves. The wavelength of the laser is preferably 1 nm to 500 μm, more preferably 10 nm or more, even more preferably 50 nm or more, even more preferably 100 nm or more, and more preferably 500 μm or less, even more preferably 50 μm or less, and even more preferably 20 μm or less. Examples of lasers include fiber lasers, YAG lasers, YVO4 lasers, organic dye lasers, CO2 lasers, Ar lasers, and copper vapor lasers. Furthermore, second and higher harmonics of these lasers may also be used. Specific examples of lasers and wavelengths include fiber lasers (1030nm~1100nm, e.g., 1064nm), YAG lasers (1064nm (fundamental wavelength), 532nm (second harmonic), 355nm (third harmonic)), YVO4 lasers (1064nm (fundamental wavelength)), CO2 lasers (10.6μm), Ar lasers (488.0nm, 514.5nm, 351.1nm, 363.8nm), and copper vapor lasers (511nm, 578nm). Furthermore, the laser output and processing speed can be appropriately selected depending on the type of laser and the antifouling paint composition used.

[0134] The antifouling coating composition of this embodiment can be used to maintain the antifouling properties of a substrate over a long period of time in a wide range of industrial fields such as ships, fisheries, and offshore structures used underwater. Examples of such substrates include ships (large steel ships such as container ships and tankers, fishing boats, FRP ships, wooden ships, yachts, etc., including hull plating, newly built or repaired ships), fishing materials (ropes, fishing nets, fishing gear, floats, buoys, etc.), oil pipelines, water intake pipes, circulating water pipes, diving suits, goggles, oxygen cylinders, swimwear, torpedoes, underwater structures such as water inlets and outlets of thermal and nuclear power plants, submarine cables, seawater utilization equipment (seawater pumps, etc.), megafloats, coastal roads, underwater tunnels, port facilities, and various marine civil engineering structures in canals and waterways. Among these, the substrate is preferably selected from the group consisting of ships, underwater structures, and fishing materials, more preferably from the group consisting of ships and underwater structures, and even more preferably a ship. Furthermore, the substrate on which the antifouling coating film of the antifouling coating composition of this embodiment is formed may be a surface treated with other treatment agents such as rust inhibitors, or a surface that already has a coating film such as a primer formed on it, or it may be applied as a topcoat to a surface that has already been painted with the antifouling coating composition of the present invention, and the type of coating film that the antifouling coating film of the present invention directly contacts is not particularly limited. [Examples]

[0135] The present invention will be described in more detail below based on examples, but the present invention is not limited to these examples.

[0136] [Production of polymer (D22) solution] <Example of polymer (D22) solution preparation> The reaction was carried out under atmospheric pressure and a nitrogen atmosphere. 42.86 g of methyl amyl ketone was charged into a reaction vessel equipped with a stirrer, reflux condenser, thermometer, nitrogen inlet tube, and dropping funnel, and heated with stirring until the internal temperature reached 100°C. While maintaining the temperature of the methyl amyl ketone in the reaction vessel within a range of 100 ± 5°C, a mixture consisting of 40.0 g of NK ester AM-90G (methoxypolyethylene glycol acrylate, polyethylene glycol repeat count = average 9, manufactured by Shin Nakamura Chemical Industry Co., Ltd.), 60.0 g of isobutyl acrylate, and 4.0 g of 2,2'-azobis(2-methylbutyronitrile) was added dropwise to the reaction vessel over 4 hours. Subsequently, the mixture was stirred for 2 hours while maintaining the same temperature range to obtain a solution containing a polymer (D22) with a solid content of 70.3% by mass, a viscosity of 109 mPa·s, and a weight-average molecular weight (Mw) of 9,100.

[0137] [Methods for evaluating polymers and polymer solutions] <Solid content (mass%) of polymer solution> 1.0 g (X1) of the polymer solution was kept in a constant temperature bath at 1 atmosphere and 108°C for 3 hours to remove volatile components and obtain non-volatile components. The amount of this non-volatile component (X2 (g)) was measured, and the solid content (mass%) of the polymer solution was calculated based on the following formula. Solid content (mass%) of polymer solution = X² / X¹ × 100

[0138] <Viscosity of polymer solution> The viscosity (unit: mPa·s) of a polymer solution at a liquid temperature of 25°C was measured using an E-type viscometer (TV-25, manufactured by Toki Sangyo Co., Ltd.).

[0139] [Antifouling paint composition] ·Ingredients Tables 1 and 2 show the components used in the antifouling paint composition. Note that the polydimethylsiloxane (A) shown in Table 1, which has methyl isobutyl ketoxime groups at both ends, has R in formula (A1). 11 is a vinyl group, R 12 is a methyl isobutyl ketoxime group, and R 13 The compound is a curable organopolysiloxane (A) in which is a methyl group and r is 1. These compound products of curable organopolysiloxane (A) and inorganic filler (silica) (C) were obtained by kneading the curable organopolysiloxane and inorganic filler (silica) (C) in the amounts shown in Table 1 using a known method.

[0140] <Measurement of the detection frequency of particles with particle diameters of 20 μm or more, 10 μm or more, 5 μm or more, and 1 μm or more, relative to the total number of particles contained in the antifouling paint composition> The particle size distribution is measured by filling the circulation chamber of a laser diffraction particle size analyzer (Microtrac-Bell Co., Ltd., MT-3300EXII) with xylene, adding an appropriate amount of xylene dispersion of paint to adjust to the correct concentration, dispersing it for 10 minutes using the ultrasonic disperser built into the device, acquiring the data, and calculating it using a refractive index of 1.81.

[0141] [Table 1]

[0142] [Table 2]

[0143] [Antifouling paint compositions 1-11] <Manufacturing of antifouling paint compositions> Each component was mixed and stirred according to the proportions (parts by mass) listed in Table 3 to prepare one-component antifouling coating compositions (antifouling coating compositions 1 to 11).

[0144] [Table 3]

[0145] <Antifouling coating composition of Comparative Example 1> A coating composition described as Comparative Example 2 in International Publication No. 2019 / 216413 was prepared to create antifouling coating composition 12. Specifically, it is as follows: (Preparation of silyl ester copolymer solution (A-1)) All reaction steps were carried out under a nitrogen atmosphere. 53.85 parts by mass of xylene were charged into a reaction vessel equipped with a stirrer, condenser, thermometer, dropping device, nitrogen inlet tube, and heating / cooling jacket, and heated to 80±3°C while stirring. While maintaining the same temperature, a monomer mixture consisting of 50.0 parts by mass of triisopropylsilyl methacrylate, 28.0 parts by mass of methoxyethyl methacrylate, 14.0 parts by mass of methyl methacrylate, 8.0 parts by mass of butyl acrylate, and 1.3 parts by mass of 2,2'-azobisisobutyronitrile was added dropwise to the reaction vessel from the dropping device over 2 hours. After stirring at the same temperature for 1 hour and then at 85°C for 1 hour, the temperature was raised to 105°C over 3 hours while adding 0.4 parts by mass of 2,2'-azobisisobutyronitrile in four portions. To the resulting reaction solution, 12.81 parts by mass of xylene was added to obtain a pale yellow, transparent silyl ester copolymer solution (A-1). The solid content in the copolymer solution was 60.6% by mass, the viscosity of the copolymer solution (at 25°C) measured with an E-type viscometer (Toki Sangyo Co., Ltd.) was 1,765 mPa·s, and the number-average molecular weight (Mn) of the copolymer, measured using GPC according to the method described in paragraph 0118 of the above-mentioned international publication, was 9,400, and the weight-average molecular weight (Mw) was 28,700. The above copolymer solution (A-1) is 22.0 parts by mass, rosin (WW rosin) is 2.8 parts by mass, cuprous oxide (NC-803, manufactured by NC-Tech Co., Ltd.) is 45.0 parts by mass, copper pyrithione (Copper Omadine Powder, manufactured by Arch UK Biocides Ltd.) is 2.0 parts by mass, red iron oxide (red iron oxide) is 2.0 parts by mass, three types of zinc oxide are 5.0 parts by mass, talc is 5.0 parts by mass, xylene is 11.8 parts by mass, fatty acid amide (Disparon 6900-20X, manufactured by Kusumoto Chemical Co., Ltd., solids content 20% by mass) is 2.0 parts by mass, polyethylene oxide (ASA D-120, manufactured by Ito Oil Co., Ltd., solids content 20% by mass) is 2.0 parts by mass, and alkoxysilane (ethyl silicate 28, manufactured by Corcol Co., Ltd., solids content 97% by mass) is 2.0 parts by mass. 1.0 part by mass (100 parts by mass in total of each component) was mixed to prepare the antifouling paint composition 12.

[0146] <Preparation of antifouling coating> (Preparation of the antifouling coating in the example) Sandblasted steel plate (200mm x 100mm x 2.3mm thick) or rigid polyvinyl chloride plate (50mm x 50mm x 1.5mm thick) was coated with epoxy resin-based anticorrosive paint ("Banno 500" manufactured by Chugoku Marine Paints Ltd.) using an air spray so that the average film thickness after drying (curing) was 100 μm, and it was dried (cured) at room temperature (23°C) for 6 hours. Next, silicone resin-based tie coat ("CMP Bioclean Tie Coat" manufactured by Chugoku Marine Paints Ltd.) was coated with an air spray so that the average film thickness after drying (curing) was 100 μm, and it was dried (cured) at room temperature for 6 hours to form an intermediate layer. Then, the antifouling paint composition of the example was painted onto this intermediate layer at room temperature so that the average film thickness after drying (curing) was 200 μm, and it was dried at room temperature for 1 week. The coating applied to the sandblasted steel plate was used for evaluations of groove formation, degree of blackening, stain resistance maintenance evaluation 1, and degree of discoloration after immersion, as described below. The coating applied to the rigid polyvinyl chloride board was used for evaluation of stain resistance maintenance evaluation 2.

[0147] (Preparation of the antifouling coating film in Comparative Example 1) A sandblasted steel plate (200 mm long x 100 mm wide x 2.3 mm thick) was coated with epoxy resin-based anticorrosive paint ("Banno 500" manufactured by Chugoku Marine Paints Ltd.) using an air spray so that the average film thickness after drying (curing) was 100 μm, and it was dried (cured) at room temperature (23°C) for 6 hours. Next, antifouling paint composition 12 was applied at room temperature so that the average film thickness after drying (curing) was 200 μm, and it was dried at room temperature for 1 week.

[0148] (Processing using fiber laser) Using a laser processing device (Speedy400 flexx, manufactured by Trotec Laser Japan Co., Ltd.), a fiber laser (laser output 50W, processing speed 10cm / s, PPI (pulses per inch): 20000Hz, resolution 250) was irradiated onto a 2cm x 3cm area in the center of the coating on the test plate, so that the groove direction was parallel to the long side of the test plate, and the surface of the coating was cut to form adjacent grooves at 100μm intervals.

[0149] (Processing using CO2 laser) Using a laser processing device (Speedy100, manufactured by Trotec Laser Japan Co., Ltd.), a CO2 laser (laser output 30W, processing speed 60cm / s, PPI (pulses per inch): 1000Hz, resolution 1000) was irradiated onto a 2cm x 3cm area in the center of the coating on the test plate, so that the groove direction was parallel to the long side of the test plate, and the surface of the coating was cut to form adjacent grooves at 100μm intervals.

[0150] <Rating> [Groove formation] As described above, when the processed areas on the surface of the prepared coating films were observed with a laser microscope, it was confirmed that grooves approximately 50 μm deep were formed in each of the coating films of Examples 1 to 21. The groove formation ability was evaluated according to the following (criteria for evaluating groove formation ability). In Comparative Example 1, the coating film surface was rough and disintegrated, and no grooves were formed (evaluation: 1), so subsequent evaluations (blackness, antifouling maintenance evaluation) were not performed. (Evaluation criteria for groove formation) 4: Grooves can be formed uniformly. 3: Grooves can be formed, but there are rough surfaces inside the grooves. 2: Grooves can be formed, but they are distorted grooves. 1: Grooves cannot be formed.

[0151] 〔Degree of blackening〕 The processed parts on the coating film surfaces of Examples 1 to 21 prepared as described above were compared with the unprocessed parts, and the degree of blackening (degree of change to black in hue) was evaluated. The degree of blackening was measured using a SPECTROPHOTOMETER CM-3700A (light source: C, field of view: 65°) manufactured by Konica Minolta Japan Co., Ltd. to measure the brightness difference (ΔL) between the processed part and the unprocessed part, and this was used as the evaluation of the degree of blackening. The smaller the absolute value of the brightness difference, the lower the degree of blackening. Examples 1 to 21 all had a small degree of blackening and were excellent in that they did not impair the aesthetic appearance.

[0152] 〔Evaluation of antifouling property maintenance 1〕 The test plates with coating films of Examples 1 to 21 prepared as described above were immersed at a position about 2 meters below the water surface in Hiroshima Bay. Three months after starting the immersion under these conditions, the adhesion areas of marine organism-derived deposits on the processed and unprocessed parts of the antifouling coating film were measured, and the antifouling property of the antifouling coating film was evaluated according to the following 〔Evaluation criteria for antifouling property based on the adhesion area of marine organism-derived deposits〕. The difference obtained by subtracting the evaluation score of the unprocessed part from the evaluation score of the processed part was calculated, and this was used as the score for the evaluation of antifouling property maintenance. The smaller this score, the less the decrease in antifouling property due to laser processing and the better the antifouling property is demonstrated. (Evaluation criteria for antifouling property based on the adhesion area of marine organism-derived deposits) 5: The total area occupied by marine organism-derived deposits on the test surface is less than 1% of the whole. 4: The same area is 1% or more and less than 10% of the whole. 3: The same area is 10% or more and less than 30% of the whole. 2: The same area is 30% or more and less than 70% of the whole. 1: The same area is 70% or more of the whole. Examples 1 to 21 are all excellent in that the difference in the amount of marine organism-derived deposits between the processed and unprocessed parts is small and they exhibit excellent maintenance of antifouling property. The results described above are shown in Tables 4 and 5 below.

[0153] [Fouling resistance maintenance evaluation 2] As described above, the test plates with antifouling coatings from Examples 1 to 10 were fixed to the side of a rotating drum and rotated at a speed of 10 knots in an outdoor tank filled with seawater that was being replaced at a constant rate. Five months after the start of immersion under these conditions, the degree of algal deposits on the processed and unprocessed areas of the antifouling coating was evaluated according to the following (evaluation criteria for antifouling against algal deposits). The difference between the evaluation score of the processed area and the evaluation score of the unprocessed area was calculated and used as the score for antifouling maintenance evaluation 2. A smaller score indicates less reduction in antifouling performance due to laser processing and better antifouling performance. (Evaluation criteria for antifouling properties against algal deposits) 4: There is almost no algal deposits attached to the test surface. 3: A thin layer of algal deposits is present on less than 50% of the entire test surface. 2: A thin layer of algal deposits is present on more than 50% of the entire test surface. 1: More than 50% of the entire test surface is covered with thick algal deposits. Examples 1 to 10 all exhibit excellent antifouling properties, as the difference in the amount of marine organism-derived deposits between the processed and unprocessed areas is small. The results described above are shown in Table 4 below.

[0154] [Table 4]

[0155] [Table 5]

[0156] The coating film formed with the underwater antifouling coating composition of the present invention exhibited excellent groove formation properties when irradiated with a laser, resulting in the formation of a riblet structure. On the other hand, the coating film formed with the underwater antifouling coating composition of the comparative example could not form grooves. Furthermore, when a coating film formed with the underwater antifouling coating composition of the present invention was subjected to laser irradiation to form a riblet structure, the degree of blackening was suppressed, and the antifouling properties were maintained.

Claims

1. Contains a curable organopolysiloxane (A), An underwater antifouling coating composition for paint films that forms a riblet structure by laser irradiation.

2. The underwater antifouling coating composition according to claim 1, wherein the underwater antifouling coating composition contains an organosilicon crosslinking agent (B), and the content of the organosilicon crosslinking agent (B) is 1 part by mass or more and 15 parts by mass or less per 100 parts by mass of curable organopolysiloxane (A).

3. The underwater antifouling paint composition according to claim 1, wherein the underwater antifouling paint composition contains an organosilicon crosslinking agent (B), and the organosilicon crosslinking agent (B) contains oximsilane.

4. The underwater antifouling coating composition according to claim 1, wherein the underwater antifouling coating composition contains an inorganic filler (C), and the total content of the inorganic filler (C) is 5 parts by mass or more and 60 parts by mass or less per 100 parts by mass of curable organopolysiloxane (A).

5. The underwater antifouling coating composition according to claim 1, wherein the underwater antifouling coating composition contains silica as an inorganic filler (C), and the silica content is 1 part by mass or more and 30 parts by mass or less per 100 parts by mass of curable organopolysiloxane (A).

6. The underwater antifouling paint composition according to claim 1, wherein the underwater antifouling paint composition contains a pigment containing a component derived from Fe as an inorganic filler (C), and the content of the pigment containing the component derived from Fe is 1 part by mass or more and 30 parts by mass or less per 100 parts by mass of curable organopolysiloxane (A).

7. The underwater antifouling paint composition according to claim 1, wherein the underwater antifouling paint composition contains at least one selected from yellow iron oxide, red iron oxide, and black iron oxide as an inorganic filler (C), and the total content of yellow iron oxide, red iron oxide, and black iron oxide is 1 part by mass or more and 30 parts by mass or less per 100 parts by mass of curable organopolysiloxane (A).

8. The underwater antifouling paint composition according to claim 1, wherein the underwater antifouling paint composition contains an inorganic filler other than titanium dioxide as an inorganic filler (C), and the content of the inorganic filler other than titanium dioxide is 1 part by mass or more and 30 parts by mass or less per 100 parts by mass of curable organopolysiloxane (A).

9. The underwater antifouling coating composition according to claim 1, wherein the detection frequency of particles with a particle diameter of 20 μm or more is 10% or less of the total particles contained in the underwater antifouling coating composition.

10. The underwater antifouling paint composition according to claim 1, wherein the underwater antifouling paint composition contains a slip agent (D), and the total content of the slip agent (D) is 5 parts by mass or more and 120 parts by mass or less per 100 parts by mass of curable organopolysiloxane (A).

11. The underwater antifouling paint composition according to claim 10, wherein the slip agent (D) contains one or more selected from the group consisting of silicone oil (D1) and polymers (D2) containing structural units derived from hydrophilic group-containing unsaturated monomers.

12. The underwater antifouling coating composition according to claim 11, wherein the content of a polymer (D2) containing constituent units derived from a hydrophilic group-containing unsaturated monomer is 10 parts by mass or less per 100 parts by mass of a curable organopolysiloxane (A).

13. A method for manufacturing an antifouling coating film having a riblet structure on its surface, comprising the following steps (1) and (2) in this order. Step (1): A step of forming an antifouling coating film on a substrate using the underwater antifouling coating composition according to any one of claims 1 to 12. Step (2): A step of irradiating the surface of the antifouling coating with a laser to form a riblet structure.

14. A method for producing an antifouling coating film according to claim 13, wherein the riblet depth of the riblet structure is 1 μm or more and 100 μm or less.

15. The method for manufacturing an antifouling coating according to claim 13, wherein the substrate is a ship.

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