Multilayer coated substrate

Abstract

To provide a substrate with a multilayer coating film that has excellent adhesion between an antifouling coating film and an epoxy resin coating film formed thereon, even without roughening the surface of the antifouling coating film. [Solution] The substrate has a multilayer coating film, which comprises, in this order: a substrate; an antifouling coating film A1 containing a silyl ester polymer (a1) having a structural unit derived from trialkylsilyl methacrylate (a11); and an epoxy resin coating film S1.

Description

[Technical Field]

[0001] The present invention relates to a substrate with a multilayer coating film and a method for producing the same. [Background technology]

[0002] The surfaces of substrates exposed (for long periods) to water (oceans, rivers, lakes, etc.), such as ships, underwater structures, and fishing nets, are prone to the attachment and proliferation of various aquatic organisms, including animals such as oysters, mussels, and barnacles, plants such as seaweed, and bacteria. The attachment and proliferation of these aquatic organisms on the substrate surface can cause various problems. For example, if the substrate is a ship, the surface roughness increases from the waterline to the bottom of the ship, which can result in a decrease in the ship's speed and increased fuel consumption. Furthermore, if the substrate is an underwater structure, the corrosion-resistant coating applied to the substrate surface can be damaged, resulting in damage such as a decrease in the strength and functionality of the corrosion-resistant coating and a significant shortening of its lifespan. Furthermore, if the substrate is a fishing net, such as an aquaculture net or a fixed net, the mesh can be blocked by aquatic organisms, causing serious problems such as the death of cultured or caught organisms due to oxygen deprivation. Furthermore, if the substrate is a seawater supply and drainage pipe in a thermal power plant or nuclear power plant, the seawater (cooling water) supply and drainage pipe may become clogged or the flow rate may decrease, causing problems in the circulation system.

[0003] To prevent problems caused by the adhesion and proliferation of various aquatic organisms, various antifouling paints are applied to various substrates to form antifouling coating films, such as hydrolyzable silyl ester copolymer-based antifouling paints and hydrolyzable cross-linked metal salt copolymer-based antifouling paints. The antifouling coating film inhibits the attachment and proliferation of various aquatic organisms, and is therefore usually formed on the outermost surface of the substrate (the outermost surface on the side opposite the substrate).

[0004] However, when an antifouling coating film is used for a long period of time, it will wear out, deteriorate, break, peel off, etc., and therefore, in order to maintain its antifouling performance, it is necessary to periodically repair or repaint the antifouling coating film. Prior to such repair painting or repainting, removing the worn or deteriorated antifouling coating film (hereinafter also referred to as the "old antifouling coating film") from the substrate surface would require extra work and expense, so from the standpoints of economy and work efficiency, it is desirable to repair and paint a new antifouling paint directly on top of the old antifouling coating film.However, when painting a new antifouling paint over the surface of such an old antifouling coating film, there are often problems with the adhesion of the antifouling coating film formed from the newly applied antifouling paint (new antifouling coating film) to the old antifouling coating film. For this reason, an epoxy resin coating film may be formed on the old antifouling coating film before a new antifouling paint is applied on top of the old antifouling coating film (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2006 / 109600 Summary of the Invention [Problem to be solved by the invention]

[0006] In recent years, when painting organopolysiloxane-based antifouling paints on newly built ships, the surface of the old antifouling paint applied in the final dock before launching is roughened with a power tool equipped with a nonwoven abrasive material, and then an epoxy resin-based paint film or the like is formed (hereinafter, this method is also referred to as the "epoxy coat system"). However, in the past, this epoxy coat system was generally applied when the old antifouling paint film was an antifouling paint formed from a cross-linked metal salt copolymer-based antifouling paint.

[0007] On the other hand, it has become clear that there is a need to improve the epoxy coating system in recent years due to factors such as the increasing demand for silicone-based antifouling paints, the need for antifouling performance when the period from launch to final docking is extended due to changes in the marine environment, and the increasing demand for use in rivers (freshwater environments) where cross-linked metal salt copolymer-based antifouling paints cannot be used. Furthermore, since the roughening process is time-consuming and expensive, it is desirable from the standpoints of economy and work efficiency to be able to form a multilayer coating film that exhibits excellent adhesion between the old antifouling coating film and the epoxy resin-based coating film without roughening the surface.

[0008] The present invention has been made in view of the above, and an object of the present invention is to provide a substrate with a multilayer coating film that exhibits excellent adhesion between the antifouling coating film and the epoxy resin coating film formed thereon, even without roughening the surface of the antifouling coating film. [Means for solving the problem]

[0009] As a result of extensive research, the present inventors have found that the above-mentioned problems can be solved by the following configuration example, and have thus completed the present invention. An example of the configuration of the present invention is as follows.

[0010] In this specification, the numerical range "A to B" indicates A or more and B or less. In this specification, the term "(co)polymer having a constitutional unit derived from compound X" refers to a (co)polymer obtained using compound X as a raw material, and refers to a (co)polymer containing a structure based on compound X through a polymerization reaction or the like. In the following description, "(meth)acrylate," "(meth)acryloyl," and "(meth)acrylic acid" mean "acrylate and / or methacrylate," "acryloyl and / or methacryloyl," and "acrylic acid and / or methacrylic acid," respectively.

[0011] [1] Base material, An antifouling coating film A1 containing a silyl ester polymer (a1) having a structural unit derived from trialkylsilyl methacrylate (a11), and Epoxy resin coating S1 A substrate with a multilayer coating film, comprising:

[0012] [2] Base material, an antifouling coating film A1 containing a silyl ester polymer (a1) having a structural unit derived from trialkylsilyl methacrylate (a11); Epoxy resin coating S1, and Organopolysiloxane antifouling coating film A2 The substrate with a multilayer coating film according to [1], comprising the following in this order:

[0013] [3] The substrate with a multilayer coating film according to [2], which comprises a silicone-based tie coat T1 between the epoxy resin-based coating film S1 and the organopolysiloxane-based antifouling coating film A2.

[0014] [4] The substrate with a multilayer coating film according to any one of [1] to [3], wherein the antifouling coating film A1 further contains copper or a copper compound (a2). [5] The substrate with a multilayer coating film according to any one of [1] to [4], wherein the content of the silyl ester polymer (a1) in the antifouling coating film A1 is 5 to 50 mass %. [6] The substrate with a multilayer coating film according to any one of [1] to [5], wherein the content of structural units derived from trialkylsilyl methacrylate (a11) in the antifouling coating film A1 is 3 to 15 mass %.

[0015] [7] The substrate with a multilayer coating film according to any one of [1] to [6], wherein the epoxy resin coating film S1 is a coating film formed from a composition S1 containing an epoxy resin, an amine curing agent, and a pigment.

[0016] [8] The substrate with a multilayer coating film according to [2] or [3], wherein the organopolysiloxane-based antifouling coating film A2 is a coating film formed from a composition A2 containing a curable polyorganosiloxane and a slipping agent. [9] The substrate with a multilayer coating film according to [8], wherein the slipping agent is at least one selected from the group consisting of silicone oil, paraffin oil, oils and fats, (meth)acrylic polymers having hydrophilic groups, polyglycerin esters, and polyalkylene glycols.

[0017]

[10] A step (i) of cleaning the antifouling coating film R1 of a substrate having an antifouling coating film R1 to be repaired or repainted; and Step (ii) of forming an epoxy resin coating film S1 on the antifouling coating film R1 after step (i). Including, the antifouling coating film R1 is an antifouling coating film formed from a composition containing a silyl ester polymer having a structural unit derived from triisopropylsilyl methacrylate, A method for producing a substrate with a multilayer coating film.

[0018]

[11] A method for producing a substrate with a multilayer coating film according to

[10] , comprising step (iii) of forming an organopolysiloxane-based antifouling coating film A2 on the side opposite to the substrate of the epoxy resin-based coating film S1 formed in step (ii).

[0019]

[12] Step (iv) of forming a silicone-based tie coat T1 on the side opposite to the substrate of the epoxy resin-based coating film S1 formed in step (ii); and The method for producing a substrate with a multilayer coating film according to

[10] or

[11] , further comprising a step (v) of forming an organopolysiloxane-based antifouling coating film A2 on the side of the silicone-based tie coat T1 formed in the step (iv) opposite to the epoxy resin-based coating film S1.

[0020]

[13] The method for producing a substrate with a multilayer coating film according to any one of

[10] to

[12] , which does not include a step of roughening the surface of the antifouling coating film R1 after step (i) between step (i) and step (ii). [Effects of the Invention]

[0021] According to the present invention, it is possible to provide a substrate with a multilayer coating film that exhibits excellent adhesion between the antifouling coating film and the epoxy resin coating film formed thereon, even without roughening the surface of the antifouling coating film. In particular, according to the present invention, it is possible to provide a substrate with a multilayer coating film that exhibits excellent adhesion between the antifouling coating film and the epoxy resin coating film formed thereon, even if the antifouling coating film is an old antifouling coating film, and the surface of the old antifouling coating film is not roughened. Furthermore, according to one embodiment of the present invention, it is possible to provide a substrate with a multilayer coating film that has excellent adhesion between all layers of the multilayer coating film, including an antifouling coating film that can be formed on the epoxy resin-based coating film. As described above, according to the present invention, a substrate with a multilayer coating film having excellent adhesion between layers can be provided without roughening the surface of the antifouling coating film, and therefore, the desired substrate with a multilayer coating film can be obtained by a method that is excellent in terms of economy, work efficiency, etc. DETAILED DESCRIPTION OF THE INVENTION

[0022] <Substrate with multilayer coating> The substrate with a multilayer coating film according to the present invention (hereinafter also referred to as "substrate with the present multilayer coating film") comprises, in this order: a substrate; an antifouling coating film A1 containing a silyl ester-based polymer (a1) having a structural unit derived from trialkylsilyl methacrylate (a11); and an epoxy resin-based coating film S1. As a result of extensive investigations, the present inventors have found, although the reason is not clear, that only when the antifouling coating film A1 contains a silyl ester-based polymer (a1) having structural units derived from trialkylsilyl acrylate but not a silyl ester-based polymer not having structural units derived from trialkylsilyl methacrylate (a11), can a substrate with a multilayer coating film exhibiting excellent adhesion between the antifouling coating film A1 and the epoxy resin-based coating film S1 formed thereon be obtained without roughening the surface of the antifouling coating film A1; further, regardless of the type of epoxy resin-based coating film S1, a substrate with a multilayer coating film exhibiting excellent adhesion between the antifouling coating film A1 and the epoxy resin-based coating film S1 formed thereon can be obtained; and further, a substrate with a multilayer coating film exhibiting excellent adhesion between all layers of the multilayer coating film, including the tie coat T1 and the antifouling coating film A2 that may be formed on the epoxy resin-based coating film S1, can be obtained.

[0023] The substrate with the present multilayer coating film is not particularly limited as long as it comprises the substrate, the antifouling coating film A1, and the coating film S1 in this order, but from the standpoint of better exerting the effects of the present invention, it is preferable that the antifouling coating film A1 and the coating film S1 are in contact with each other. The substrate with the multilayer coating film preferably comprises a substrate, an antifouling coating film A1, a coating film S1, and an organopolysiloxane-based antifouling coating film A2 in this order. From the viewpoint of easily obtaining a substrate with a multilayer coating film having excellent adhesion between the coating film S1 and the antifouling coating film A2, it is more preferable to include a silicone tie coat T1 between the coating film S1 and the antifouling coating film A2, that is, to include the substrate, antifouling coating film A1, coating film S1, tie coat T1, and antifouling coating film A2 in this order. In this case, it is preferable that the coating film S1 and the tie coat T1 are in contact, and it is also preferable that the tie coat T1 and the antifouling coating film A2 are in contact. The multilayer coated substrate may contain two or more layers of antifouling coating film A1, two or more layers of coating film S1, two or more layers of tie coat T1, and / or two or more layers of antifouling coating film A2, but typically there is one layer each of antifouling coating film A1, coating film S1, tie coat T1, and antifouling coating film A2. The substrate with the multilayer coating film may include films (layers) other than the antifouling coating film A1, the coating film S1, the tie coat T1, and the antifouling coating film A2.

[0024] <Anti-fouling coating film A1> The antifouling coating film A1 contains a silyl ester polymer (a1) having a structural unit derived from trialkylsilyl methacrylate (a11), and is preferably formed from the following antifouling coating composition A1.

[0025] The antifouling coating film A1 may be an old antifouling coating film that has been worn or deteriorated due to exposure to water (oceans, rivers, lakes, marshes, etc.) for a certain period of time and that needs to be repaired or repainted, i.e., an old antifouling coating film, but from the viewpoint of better exerting the effects of the present invention, it is preferable that it is an old antifouling coating film. Such an old antifouling coating film may be referred to below as "old antifouling coating film A1" and / or "antifouling coating film R1". Furthermore, the description of "antifouling coating film A1" in this specification also applies to "old antifouling coating film A1" and "antifouling coating film R1".

[0026] The old antifouling coating film may be, for example, an antifouling coating film after a predetermined service life has elapsed. Antifouling coating films formed from antifouling paints that are applied to the bottoms of ships and the like generally have a set service life appropriate for each type of operation, and are usually repainted after the service life has expired. Specifically, the service life is 3 to 6 months for small vessels such as fishing boats and pleasure boats, and 12 to 90 months for large vessels such as crude oil tankers and container ships. In this way, the service life varies widely depending on the vessel's operating mode, such as its route, and is not particularly limited.

[0027] The thickness of the antifouling coating film A1 is selected arbitrarily depending on the renewal rate of the antifouling coating film A1, the period of use, etc., but is preferably about 30 to 1,000 μm, more preferably about 40 to 850 μm, and even more preferably about 50 to 700 μm.

[0028] [Antifouling coating composition A1] The antifouling coating composition A1 contains a silyl ester polymer (a1) having a structural unit derived from trialkylsilyl methacrylate (a11).

[0029] [Silyl ester polymer (a1)] The silyl ester polymer (a1) is not particularly limited as long as it has a structural unit derived from trialkylsilyl methacrylate (a11). It may be a (co)polymer consisting of (only) one or more structural units derived from trialkylsilyl methacrylate (a11), or may be a copolymer (a11-12) having a structural unit derived from trialkylsilyl methacrylate (a11) and a structural unit derived from an ethylenically unsaturated monomer (a12) other than trialkylsilyl methacrylate (a11), and such copolymer (a11-12) is preferred. The polymer (a1) used in the composition A1 may be one type or two or more types.

[0030] <Trialkylsilyl methacrylate (a11)> Examples of the trialkylsilyl methacrylate (a11) include trimethylsilyl methacrylate, triethylsilyl methacrylate, tripropylsilyl methacrylate, triisopropylsilyl methacrylate, tributylsilyl methacrylate, triisobutylsilyl methacrylate, tri-sec-butylsilyl methacrylate, tri-2-ethylhexylsilyl methacrylate, and butyldiisopropylsilyl methacrylate. Among these, trialkylsilyl methacrylates having a branched alkyl group are preferred, and triisopropylsilyl methacrylate is particularly preferred, from the viewpoint of being able to easily form an antifouling coating film A1 that is excellent in a well-balanced manner in long-term antifouling properties and crack resistance. As the (a11) used in the synthesis of the copolymer (a11-12), one type may be used, or two or more types may be used.

[0031] The content of structural units derived from (a11) relative to 100% by mass of all structural units in copolymer (a11-12) is preferably 35 to 75% by mass, more preferably 40 to 70% by mass, and even more preferably 45 to 70% by mass, from the viewpoint of easily obtaining an antifouling coating film A1 that has good water resistance and antifouling properties over a long period of time. In particular, when the content of structural units derived from (a11) is 45 to 70% by mass, an antifouling coating film A1 that is more excellent in water resistance and crack resistance can be easily formed.

[0032] The content of structural units derived from (a11) in the antifouling coating film A1 is preferably 3 to 15 mass %, more preferably 4 to 13 mass %, and even more preferably 5 to 10 mass %, from the viewpoint that a substrate with a multilayer coating film having excellent adhesion between the antifouling coating film A1 and the coating film S1 formed thereon can be easily obtained. If the content of the structural units derived from (a11) in the antifouling coating film A1 is less than the above-mentioned lower limit, the adhesion of the antifouling coating film A1 to the coating film S1 may decrease, so that a substrate with a multilayer coating film having better adhesion between the antifouling coating film A1 and the coating film S1 can be easily obtained, and therefore the content of the structural units derived from (a11) in the antifouling coating film A1 is preferably at least the above-mentioned lower limit. On the other hand, if the content of the structural units derived from (a11) in the antifouling coating film A1 exceeds the above-mentioned upper limit, the antifouling properties of the antifouling coating film A1 may decrease, so that an antifouling coating film A1 having better antifouling properties can be easily formed, and therefore the content of the structural units derived from (a11) in the antifouling coating film A1 is preferably at most the above-mentioned upper limit. This content can be calculated by multiplying the content of polymer (a1) in the antifouling coating film A1 by the content of structural units derived from (a11) in the polymer (a1).

[0033] The copolymer (a11-12) may have a structure derived from the polymerization initiator at its terminal. The content of the structural unit derived from (a11) can be approximated by the charge ratio (mass ratio) of (a11) to all the monomer components used in synthesizing the copolymer (a11-12). The same applies to the content of other structural units.

[0034] <Monomer (a12)> The monomer (a12) is not particularly limited as long as it is an ethylenically unsaturated monomer other than trialkylsilyl methacrylate (a11), but it preferably contains 2-methoxyethyl (meth)acrylate (a12-1), and more preferably contains (a12-1) and an ethylenically unsaturated monomer (a12-2) other than these.

[0035] 2-Methoxyethyl (meth)acrylate (a12-1) The copolymer (a11-12) preferably contains a structural unit derived from (a12-1) because this allows for the easy formation of an antifouling coating film A1 with even more excellent antifouling properties. When (a12-1) is used to synthesize the copolymer (a11-12), 2-methoxyethyl acrylate, 2-methoxyethyl methacrylate, or 2-methoxyethyl acrylate and 2-methoxyethyl methacrylate may be used.

[0036] The content of structural units derived from (a12-1) relative to 100% by mass of all structural units in copolymer (a11-12) is preferably 15 to 35% by mass, more preferably 20 to 35% by mass, and even more preferably 20 to 30% by mass, from the viewpoint of easily forming an antifouling coating film A1 with stable wear resistance and antifouling properties. In particular, when the content of structural units derived from (a12-1) is 20 to 30% by mass, the copolymer has appropriate hydrophilicity, making it easy to form an antifouling coating film A1 that can achieve both antifouling and crack resistance. Furthermore, 2-methoxyethyl methacrylate is preferred from the viewpoint of achieving the same effect.

[0037] The total content of the structural units derived from (a11) and the structural units derived from (a12-1), relative to 100% by mass of all structural units in copolymer (a11-12), is preferably 60 to 99% by mass, more preferably 70 to 98% by mass, even more preferably 75 to 95% by mass, and particularly preferably 75 to 90% by mass, from the viewpoint of being able to easily form an antifouling coating film A1 that has excellent antifouling properties and physical properties.

[0038] Other ethylenically unsaturated monomers (a12-2) There are no particular restrictions on (a12-2) as long as it is an ethylenically unsaturated monomer other than the above (a11) and (a12-1), but the oligomers and polymers described below are excluded. When (a12-2) is used to synthesize the copolymer (a11-12), one type of (a12-2) may be used, or two or more types may be used.

[0039] As (a12-2), for example, Unsaturated carboxylic acids such as (meth)acrylic acid, (meth)acryloyloxyalkyl succinic acid, (meth)acryloyloxyalkyl phthalic acid, (meth)acryloyloxyalkyl hexahydrophthalic acid, itaconic acid, and maleic acid; (meth)acrylic acid esters such as alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate, and stearyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, isobornyl (meth)acrylate, glycidyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, methoxytriethylene glycol (meth)acrylate, ethoxydiethylene glycol (meth)acrylate, and methoxydipropylene glycol (meth)acrylate; acrylic acid silyl esters such as trimethylsilyl acrylate, triethylsilyl acrylate, and triisopropylsilyl acrylate; vinyl compounds such as vinyl acetate, vinyl propionate, vinyl sulfonic acid, and vinyl phosphonic acid; styrenes such as styrene and ammonium styrene sulfonate; Examples include:

[0040] Among these, unsaturated carboxylic acids, alkyl (meth)acrylates, and vinyl compounds are preferred, (meth)acrylic acid, alkyl (meth)acrylates having an alkyl group with 1 to 4 carbon atoms, and vinyl sulfonic acid are more preferred, and methyl methacrylate, butyl acrylate, (meth)acrylic acid, and vinyl sulfonic acid are particularly preferred.

[0041] The content of structural units derived from (a12-2) relative to 100% by mass of all structural units in copolymer (a11-12) is preferably 1 to 40% by mass, more preferably 2 to 30% by mass, even more preferably 5 to 25% by mass, and particularly preferably 10 to 25% by mass, from the viewpoint of being able to adjust the physical properties of the antifouling coating film A1.

[0042] <Other components other than (a11), (a12-1) and (a12-2)> The copolymer (a11-12) may have a structure derived from a component other than (a11), (a12-1) and (a12-2). When the other components are used in the synthesis of the copolymer (a11-12), one type of the other components may be used, or two or more types may be used.

[0043] Examples of the other components include oligomers or polymers that have a polymerizable ethylenically unsaturated group at the end of the molecular chain and are incorporated into the structure of the copolymer (a11-12). The number average molecular weight of the oligomer or polymer is usually 500 to 30,000, and preferably 1,000 to 20,000.

[0044] Examples of the oligomers or polymers include: Macromonomers such as AA-6 (trade name, manufactured by Toagosei Co., Ltd., methacryloyl-terminated polymethyl methacrylate) and AS-6 (trade name, manufactured by Toagosei Co., Ltd., methacryloyl-terminated polystyrene); Silicones such as Silaplane FM-0711 (trade name, manufactured by JNC Corporation, polydimethyl silicone having a methacryloxy group at one end) and KF-2012 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd., polydimethyl silicone having a methacryloxy group at one end); Polymers such as alkyd resins containing unsaturated groups; Examples include:

[0045] <Solid Acid Value of Polymer (a1)> The acid value of the solid content of the polymer (a1) is preferably 0 to 10 mgKOH / g, more preferably 0.5 to 9 mgKOH / g, and even more preferably 1 to 8 mgKOH / g, from the viewpoints that an antifouling coating composition A1 that is easy to apply can be easily obtained and an antifouling coating film A1 that is excellent in long-term antifouling properties can be easily formed. "Acid value" is the number of milligrams of potassium hydroxide required to neutralize the free acid present in 1 g of sample, and is expressed in units of "mgKOH / g." Specifically, the acid value of the solid content can be measured by the method described in the examples.

[0046] The acid group that gives the polymer (a1) the acid value is not particularly limited, but examples thereof include a carboxy group, a sulfonic acid group, and a phosphoric acid group, with a carboxy group being preferred.

[0047] Examples of methods for introducing the acid group into the polymer (a1) include a method of copolymerizing a monomer having an acid group, and a method using a polymerization initiator having an acid group. Examples of the monomer having an acid group include unsaturated carboxylic acids, vinyl sulfonic acid, and vinyl phosphonic acid. Among these, unsaturated carboxylic acids and vinyl sulfonic acid are preferred, (meth)acrylic acid and vinyl sulfonic acid are more preferred, and (meth)acrylic acid is particularly preferred. The monomer having an acid group may be used alone or in combination of two or more.

[0048] The content of the monomer having an acid group is preferably adjusted so that the acid value of the solid content falls within the above range, and the content of the structural units derived from the monomer having an acid group relative to 100% by mass of all structural units of the polymer (a1) is preferably 0.01 to 5% by mass.

[0049] <Weight-average molecular weight (Mw) of polymer (a1)> The Mw of the polymer (a1) is preferably 60,000 or less, more preferably 40,000 or less. An antifouling coating film A1 formed from an antifouling coating composition A1 containing a polymer (a1) having an Mw within the above range tends to exhibit good hydrolysis resistance and good coating film abrasion cleanability (coating film wear resistance), further improved antifouling properties, and excellent long-term durability. The Mw of the polymer (a1) is preferably 12,000 or more, more preferably 13,000 or more, from the viewpoint that an antifouling coating film A1 excellent in strength, long-term durability, etc. can be easily formed. The Mw of the polymer (a1) can be measured by gel permeation chromatography (GPC), and the value obtained by GPC is a value (polystyrene-equivalent value) determined using a calibration curve prepared using polystyrene as a standard substance.

[0050] <Content of polymer (a1)> The solid content of the polymer (a1) is preferably 5 to 50 mass %, more preferably 7 to 20 mass %, relative to 100 mass % of the solid content of the antifouling coating composition A1, from the viewpoint of being able to easily form an antifouling coating film A1 that is excellent in water resistance and various physical properties (crack resistance and antifouling properties of the coating film) over a long period of time. The content of the solid content of the polymer (a1) can also be said to be the content of the polymer (a1) in the antifouling coating film A1.

[0051] The "solid content" of antifouling coating composition A1 and each raw material used in antifouling coating composition A1 refers to the mass excluding volatile components, and refers to the residue when antifouling coating composition A1 and each raw material containing volatile components such as solvents are dried in a hot air dryer at 105°C for 3 hours to volatilize the volatile components such as solvents.

[0052] [Optional ingredients] The antifouling coating composition A1 may contain optional components other than the polymer (a1) to the extent that the effects of the present invention are not impaired. Examples of the optional components include copper or a copper compound (a2), rosins and / or monocarboxylic acid compounds, organic antifouling agents, other binder components, coloring pigments, extender pigments, (pigment) dispersants, plasticizers, anti-sagging agents, anti-settling agents, dehydrating agents, and solvents.

[0053] <Copper or copper compound (a2)> The antifouling coating composition A1 may contain copper or a copper compound (a2) (excluding copper pyrithione) in order to further improve the antifouling properties of the antifouling coating film A1 to be formed. The copper or copper compound (a2) may be used alone or in combination of two or more.

[0054] The copper compound may be either an organic or inorganic copper compound. Examples of copper or copper compounds (a2) include powdered copper (copper powder), cuprous oxide, copper thiocyanate (copper rhodanide), and cupronickel. Among the copper or copper compounds (a2), cuprous oxide is more preferred from the viewpoints of antifouling properties, particularly antifouling properties against animals among aquatic organisms, and ease of forming an antifouling coating film A1 that is excellent in water resistance.

[0055] The cuprous oxide preferably contains cuprous oxide having an average particle size of about 1 to 30 μm, and more preferably contains cuprous oxide having an average particle size of 2 to 10 μm, from the viewpoint that an antifouling coating film A1 having excellent antifouling properties and water resistance can be easily formed.

[0056] The cuprous oxide is preferably surface-treated with glycerin, stearic acid, lauric acid, sucrose, lecithin, mineral oil, or the like, from the viewpoints of antifouling properties and long-term stability during storage.

[0057] The cuprous oxide may be commercially available, and examples thereof include "NC-301" (average particle size: 2 to 4 μm) manufactured by NC Tech Corporation, "NC-803" (average particle size: 6 to 10 μm) manufactured by NC Tech Corporation, "NORDOX" manufactured by Nordox Industrier AS, "Red Copp97N Premium" manufactured by AMERICAN CHEMET Co., "Purple Copp" manufactured by AMERICAN CHEMET Co., and "LoLoTint97" manufactured by AMERICAN CHEMET Co.

[0058] When the antifouling coating composition A1 contains copper or a copper compound (a2), the content thereof is preferably 20 to 80 mass%, more preferably 40 to 70 mass%, and even more preferably 40 to 65 mass%, relative to 100 mass% of the solids content of the antifouling coating composition A1, in order to facilitate the formation of an antifouling coating film A1 having excellent antifouling performance and water resistance.

[0059] <Rosins and / or monocarboxylic acid compounds> The antifouling coating composition A1 preferably contains rosins and / or monocarboxylic acid compounds, since this can further improve the antifouling properties of the antifouling coating film A1 to be formed, and in particular, can improve the static antifouling properties. Furthermore, the use of rosins and / or monocarboxylic acid compounds promotes the renewal of the resulting antifouling coating film A1 from the surface in water, and when the antifouling coating film A1 contains an antifouling agent, the use of rosins and / or monocarboxylic acid compounds promotes the release of the antifouling agent into water, thereby enhancing the antifouling properties of the antifouling coating film A1 and also tends to impart appropriate water resistance to the antifouling coating film A1. The rosins and / or monocarboxylic acid compounds may be used alone or in combination of two or more.

[0060] Preferred examples of rosins and / or monocarboxylic acid compounds include compounds in which a saturated or unsaturated aliphatic hydrocarbon having 10 to 40 carbon atoms is substituted with one carboxy group, compounds in which a saturated or unsaturated alicyclic hydrocarbon having 3 to 40 carbon atoms is substituted with one carboxy group, and compounds in which a modified aliphatic hydrocarbon or alicyclic hydrocarbon is substituted with one carboxy group. Among these, abietic acid, neoabietic acid, dehydroabietic acid, palustric acid, isopimaric acid, pimaric acid, trimethylisobutenylcyclohexenecarboxylic acid, versatic acid, stearic acid, naphthenic acid, and the like are preferred. Also preferred are rosins containing abietic acid, palustric acid, isopimaric acid, etc. Examples of rosins include gum rosin, wood rosin, tall oil rosin, and other rosin derivatives such as hydrogenated rosin, disproportionated rosin, and rosin metal salts, as well as pine tar.

[0061] An example of the trimethylisobutenylcyclohexenecarboxylic acid is the reaction product of 2,6-dimethylocta-2,4,6-triene and methacrylic acid, which is mainly composed of 1,2,3-trimethyl-5-(2-methylprop-1-en-1-yl)cyclohex-3-ene-1-carboxylic acid and 1,4,5-trimethyl-2-(2-methylprop-1-en-1-yl)cyclohex-3-ene-1-carboxylic acid (85% by mass or more).

[0062] When the antifouling coating composition A1 contains rosins and / or monocarboxylic acid compounds, the content thereof is preferably 1 to 50 mass%, more preferably 2 to 20 mass%, and even more preferably 3 to 10 mass%, relative to 100 mass% of the solid content of the antifouling coating composition A1. Furthermore, from the viewpoint of easily forming an antifouling coating film A1 having good antifouling properties and physical properties (e.g., crack resistance and coating gloss (aesthetics)), the content thereof is preferably 5 to 150 mass parts, more preferably 10 to 150 mass parts, and even more preferably 15 to 100 mass parts, relative to 100 mass parts of the solid content of the polymer (a1).

[0063] <Organic antifouling agent> The antifouling coating composition A1 may contain an organic antifouling agent (excluding copper or a copper compound (a2)). The organic antifouling agents may be used alone or in combination of two or more.

[0064] Examples of organic antifouling agents include copper pyrithione, zinc pyrithione, 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one (also known as DCOIT), 4-bromo-2-(4-chlorophenyl)-5-(trifluoromethyl)-1H-pyrrole-3-carbonitrile (also known as tralopyril), 4,5-dimethyl-1H-imidazole, (+ / -)-4-[1-(2,3-dimethylphenyl)ethyl]-1H-imidazole (also known as medetomidine), borane-nitrogen base adducts (pyridinetriphenylborane, 4-isopropylpyridinediphenylmethylborane, etc.), N,N-dimethyl-N'-(3,4-dichlorophenyl)urea, N-(2,4,6-trichlorophenyl)-2-methyl-4-isothiazolinone ... N',N'-dimethyl-N-phenyl-(N-fluorodichloromethylthio)sulfamide, tetraalkylthiuram disulfide, zinc dimethyldithiocarbamate, zinc ethylenebisdithiocarbamate, 2,3-dichloro-N-(2',6'-diethylphenyl)maleimide, 2,3-dichloro-N-(2'-ethyl-6'-methylphenyl)maleimide. Among these, copper pyrithione, 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one, and (+ / -)-4-[1-(2,3-dimethylphenyl)ethyl]-1H-imidazole are preferred, and copper pyrithione is particularly preferred.

[0065] When the antifouling coating composition A1 contains an organic antifouling agent, the content thereof is preferably 0.5 to 10 mass %, more preferably 1 to 5 mass %, relative to 100 mass % of the solids content of the antifouling coating composition A1, from the viewpoints that an antifouling coating composition A1 having excellent coating workability can be easily obtained and an antifouling coating film A1 having excellent antifouling performance and water resistance can be easily formed.

[0066] <Other binder components> The antifouling coating composition A1 may contain other binder components in addition to the polymer (a1) in order to impart static antifouling properties, water resistance, crack resistance, strength, etc. to the antifouling coating film A1 to be formed. Examples of the other binder components include acrylic (co)polymers (acrylic resins), vinyl polymers, n-paraffins, and terpene phenols. The other binder components may be used alone or in combination of two or more.

[0067] The acrylic (co)polymer preferably contains a structural unit derived from at least one selected from the group consisting of the (meth)acrylic acid esters and metal ester group-containing unsaturated monomers, for example, from the viewpoint of easily forming an antifouling coating film A1 having excellent static antifouling properties. The (meth)acrylic acid esters may be used alone or in combination of two or more.

[0068] The metal ester group-containing unsaturated monomer refers to a monomer containing a metal ester group formed by bonding a metal with a carboxylic acid. The metal ester group is preferably a polyvalent metal ester group, more preferably a divalent metal ester group. The polyvalent metal ester group or divalent metal ester group refers to a group formed by bonding a polyvalent metal or divalent metal with a carboxylic acid.

[0069] Examples of metals constituting the metal ester group include magnesium, calcium, neodymium, titanium, zirconium, iron, ruthenium, cobalt, nickel, copper, zinc, and aluminum. Among these, metals of Groups 10 to 12 such as nickel, copper, and zinc are preferred, metals selected from the group consisting of copper and zinc are more preferred, and zinc is even more preferred.

[0070] Examples of the metal ester group-containing unsaturated monomer include zinc di(meth)acrylate, copper di(meth)acrylate, zinc acrylate (methacrylate), copper acrylate (methacrylate), zinc di(3-acryloyloxypropionate), copper di(3-acryloyloxypropionate), zinc (meth)acrylate (naphthenate), and copper (meth)acrylate (naphthenate). The metal ester group-containing unsaturated monomer may be used alone or in combination of two or more.

[0071] The acrylic (co)polymer may contain structural units derived from vinyl compounds other than the (meth)acrylic acid esters and metal ester group-containing unsaturated monomers. Examples of the other vinyl compounds include styrene, α-methylstyrene, vinyl acetate, vinyl benzoate, vinyltoluene, acrylonitrile, vinylpyridine, vinylpyrrolidone, and vinyl chloride. The other vinyl compounds may be used alone or in combination of two or more.

[0072] Other commercially available binder components may also be used, such as "DIANAL BR-106" (acrylic polymer) manufactured by Mitsubishi Chemical Corporation, and acid group-containing polymers obtained by reacting a polymer containing two or more acid groups (e.g., a polyester polymer or an acrylic polymer) with the rosins and / or monocarboxylic acid compounds and metal compounds, as described in International Publication No. 2014 / 010702.

[0073] When the antifouling coating composition A1 contains other binder components, the content thereof is preferably 1 to 20% by mass relative to 100% by mass of the solid content of the antifouling coating composition A1.

[0074] <Coloring pigments> The antifouling coating composition A1 may contain a coloring pigment in order to adjust the color tone of the antifouling coating film A1 to be formed or to impart any desired color tone to the antifouling coating film A1 to be formed. One type of color pigment may be used, or two or more types may be used.

[0075] Examples of color pigments include various known organic or inorganic color pigments. Examples of organic color pigments include Pigment Black 7 (carbon black), Pigment Red 170 (naphthol red), and Pigment Blue 15 (phthalocyanine blue). Examples of inorganic color pigments include red iron oxide (red iron oxide) (Fe2O3), black iron oxide (Fe3O4), titanium oxide (titanium white / TiO2), and yellow iron oxide. The antifouling coating composition A1 may also contain a colorant other than the color pigment, such as a dye, together with or instead of the color pigment.

[0076] When the antifouling coating composition A1 contains a coloring pigment, the content thereof is preferably determined depending on the hiding power required for the antifouling coating film A1 to be formed, the desired viscosity according to the application form of the antifouling coating composition A1, etc., but is preferably 0.5 to 10 mass % relative to 100 mass % of the solids content of the antifouling coating composition A1.

[0077] <Extender pigment> The antifouling coating composition A1 may contain an extender pigment, which allows for the easy formation of an antifouling coating film A1 having excellent coating film properties such as crack resistance. One type of extender pigment may be used, or two or more types may be used.

[0078] Examples of extender pigments include talc, zinc oxide, zinc phosphate, silica (diatomaceous earth, acid clay, etc.), mica, clay, potassium feldspar, calcium carbonate, kaolin, alumina white, white carbon, aluminum hydroxide, magnesium carbonate, barium carbonate, barium sulfate, and zinc sulfide. Among these, talc, zinc oxide, zinc phosphate, silica, mica, clay, calcium carbonate, kaolin, barium sulfate, and potassium feldspar are preferred.

[0079] When the antifouling coating composition A1 contains an extender pigment, the content thereof is preferably determined depending on the hiding power required for the antifouling coating film A1 to be formed and the desired viscosity according to the application form of the antifouling coating composition A1, but is preferably 1 to 50 mass % relative to 100 mass % of the solids content of the antifouling coating composition A1.

[0080] <(Pigment) Dispersant> When the antifouling coating composition A1 contains a color pigment, an extender pigment, etc., the antifouling coating composition A1 may contain a (pigment) dispersant in order to improve the dispersibility of the color pigment, the extender pigment, etc. The (pigment) dispersant may be used alone or in combination of two or more kinds.

[0081] Examples of the (pigment) dispersant include various known organic or inorganic (pigment) dispersants, and specific examples include aliphatic amines, organic acids, and "Disperbyk-101" manufactured by BYK Corporation.

[0082] <Plasticizer> The antifouling coating composition A1 may contain a plasticizer in order to improve the crack resistance of the antifouling coating film A1 to be formed. One type of plasticizer may be used, or two or more types may be used.

[0083] Examples of plasticizers include tricresyl phosphate (TCP), chlorinated paraffin (chlorinated paraffin), petroleum resins, ketone resins, polyvinyl ethyl ether, and dialkyl phthalate. Among these, chlorinated paraffin, petroleum resins, and ketone resins are preferred because they allow for the easy formation of an antifouling coating film A1 that is excellent in water resistance and hydrolysis resistance (wear resistance).

[0084] Specific examples of chlorinated paraffins include "Toyoparax A-40 / A-50 / A-70 / A-145 / A-150" manufactured by Tosoh Corporation. Examples of petroleum resins include C5-based, C9-based, styrene-based, dichloropentadiene-based, and hydrogenated products thereof, and specific examples include "Quinton 1500 / 1700" manufactured by Zeon Corporation.

[0085] When the antifouling coating composition A1 contains a plasticizer, the content thereof is preferably 0.1 to 10 mass %, more preferably 0.5 to 5 mass %, relative to 100 mass % of the solid content of the antifouling coating composition A1, in order to maintain good plasticity of the antifouling coating film A1 to be formed.

[0086] <Anti-sagging agent> The antifouling coating composition A1 may contain an anti-sagging agent (anti-flow agent) in order to reduce the occurrence of sagging when the composition A1 is applied to a substrate. One type of anti-sagging agent may be used, or two or more types may be used.

[0087] Examples of anti-sagging agents include amide wax (fatty acid amide, etc.), hydrogenated castor oil wax, mixtures thereof, and synthetic finely powdered silica (Aerosil (registered trademark), etc.), and among these, amide wax or synthetic finely powdered silica is preferred.

[0088] The use of amide wax or synthetic finely powdered silica as an anti-sagging agent makes it possible to easily obtain an antifouling coating composition A1 having excellent storage stability, and is therefore preferred because, after the antifouling coating film A1 is formed, when a coating film (topcoat coating film) made of the same type of antifouling coating composition or a different type of coating composition is formed on the antifouling coating film A1, a decrease in adhesion (interlayer adhesion, recoatability) between the antifouling coating film A1 and the topcoat coating film can be easily suppressed.

[0089] Commercially available anti-sagging agents include "Disparlon A630-20X" and "Disparlon 4200-20" manufactured by Kusumoto Chemicals Co., Ltd., and "ASA T-250F" manufactured by Ito Oil Mills Co., Ltd.

[0090] When the antifouling coating composition A1 contains an anti-sagging agent, the content thereof is preferably 0.01 to 10 mass %, more preferably 0.1 to 3 mass %, and even more preferably 0.2 to 2 mass %, relative to 100 mass % of the solid content of the antifouling coating composition A1.

[0091] <Anti-settling agent> The antifouling coating composition A1 may contain an anti-settling agent, which can suppress the formation of precipitates and improve the stirrability during storage of the composition A1. The anti-settling agent may be used alone or in combination of two or more kinds.

[0092] Examples of the anti-settling agent include stearates of Al, Ca, or Zn, polyethylene wax, and oxidized polyethylene wax, and among these, oxidized polyethylene wax is preferred. An example of a commercially available oxidized polyethylene wax is "Disparlon 4200-20X" manufactured by Kusumoto Chemicals Co., Ltd.

[0093] When the antifouling coating composition A1 contains an anti-settling agent, the content thereof is preferably 0.01 to 10 mass %, more preferably 0.05 to 3 mass %, and even more preferably 0.1 to 2 mass %, relative to 100 mass % of the solid content of the antifouling coating composition A1.

[0094] <Dehydrating agent> The antifouling coating composition A1 has excellent storage stability because it contains the polymer (a1) which has good storage stability. However, by adding a dehydrating agent as necessary, an antifouling coating composition A1 with even better long-term storage stability can be easily obtained. The dehydrating agent may be used alone or in combination of two or more kinds.

[0095] The dehydrating agent includes inorganic dehydrating agents and organic dehydrating agents. As the inorganic dehydrating agent, synthetic zeolite, anhydrous gypsum and hemihydrate gypsum are preferred. Preferred organic dehydrating agents include alkoxy or aryloxy silanes such as tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, tetraphenoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, and trimethylethoxysilane; polyalkoxysilanes which are partial hydrolysis condensates thereof; and alkyl orthoformates such as methyl orthoformate and ethyl orthoformate. Among these, tetraethoxysilane, which is an alkoxysilane, is preferred.

[0096] When the antifouling coating composition A1 contains a dehydrating agent, the content thereof is preferably 0.01 to 10 mass%, more preferably 0.1 to 3 mass%, and even more preferably 0.15 to 1 mass%, relative to 100 mass% of the solids content of the antifouling coating composition A1, from the viewpoint that an antifouling coating composition A1 having excellent storage stability can be easily obtained.

[0097] <solvent> The antifouling coating composition A1 may contain a solvent as needed, from the viewpoints of improving the dispersibility of the polymer (a1) and the like, keeping the viscosity of the composition A1 low, and improving the spray atomization properties. The solvent may be the solvent used when synthesizing the polymer (a1), or may be a solvent added separately when mixing the polymer (a1) with optional components as needed. The solvent may be used alone or in combination of two or more.

[0098] As the solvent, aromatic hydrocarbon-based, aliphatic hydrocarbon-based, alicyclic hydrocarbon-based, ketone-based, ester-based, and alcohol-based organic solvents can be used, with aromatic hydrocarbon-based organic solvents being preferred. Examples of aromatic hydrocarbon organic solvents include toluene, xylene, and mesitylene. Examples of the aliphatic hydrocarbon organic solvent include pentane, hexane, heptane, and octane. Examples of the alicyclic hydrocarbon organic solvent include cyclohexane, methylcyclohexane, and ethylcyclohexane. Examples of the ketone organic solvent include acetylacetone, acetone, methyl ethyl ketone, methyl isobutyl ketone, and dimethyl carbonate. An example of the ester-based organic solvent is propylene glycol monomethyl ether acetate. Examples of alcohol-based organic solvents include isopropanol, n-butanol, and propylene glycol monomethyl ether.

[0099] When the antifouling coating composition A1 contains a solvent, the content thereof is determined depending on the desired viscosity and anti-sagging properties according to the application form of the antifouling coating composition A1, but is preferably 50 mass % or less, more preferably 10 to 40 mass %, and even more preferably 15 to 35 mass % relative to 100 mass % of the antifouling coating composition A1.

[0100] <Epoxy resin coating S1> The coating film S1 is not particularly limited as long as it is an epoxy resin-based coating film, and is preferably a coating film formed from a composition S1 containing an epoxy resin, an amine-based curing agent, and a pigment. The substrate with this laminated coating film has a specific antifouling coating film A1 on which coating film S1 is formed, and therefore has excellent adhesion between the antifouling coating film A1 and coating film S1. There are no particular restrictions on the type of coating film S1 as long as it is an epoxy resin-based film, and it has excellent adhesion to the antifouling coating film A1. In one embodiment of the present invention, coating S1 can also be referred to as an "epoxy sealer coat."

[0101] The thickness of the coating film S1 may be adjusted appropriately depending on the desired application, but is preferably 30 to 300 μm, more preferably 50 to 200 μm.

[0102] [Composition S1] The composition S1 preferably contains an epoxy resin, an amine-based curing agent, and a pigment. Although such composition S1 may be a one-component composition, it is usually a two-component composition consisting of a base component containing an epoxy resin and a curing agent component containing an amine-based curing agent. Furthermore, if necessary, composition S1 may be a three-component or higher composition containing components other than the base component and the curing agent component. These main component, curing agent component and other components are usually stored, preserved, transported, etc. in separate containers, and are mixed together immediately before use of the composition S1.

[0103] [Epoxy resin] The epoxy resin is preferred because it exhibits adhesive strength to the coating film it comes into contact with, has excellent mechanical properties, and is easily cured when an amine-based curing agent, which will be described later, is used. One type of epoxy resin may be used, or two or more types may be used.

[0104] The epoxy resin is not particularly limited as long as it does not impair the effects of the present invention, and examples thereof include bisphenol-type epoxy resins, glycidyl ester-type epoxy resins, glycidyl amine-type epoxy resins, novolac-type epoxy resins (e.g., phenol novolac-type epoxy resins, cresol novolac-type epoxy resins), dimer acid-modified epoxy resins, aliphatic epoxy resins, alicyclic epoxy resins, and epoxidized oil-based epoxy resins.

[0105] Among these, bisphenol A type epoxy resins, bisphenol F type epoxy resins, and novolac type epoxy resins are preferred because they have excellent adhesion to the antifouling coating film A1 and excellent corrosion resistance. Furthermore, the bisphenol A and bisphenol F epoxy resins are preferably semi-solid resins at 25°C, in order to improve the curing properties and quickly obtain a coating film S1 having practical strength. Furthermore, it is particularly preferable to use these in combination with a novolac epoxy resin rather than using them alone, in order to easily form a coating film S1 having sufficient strength without excessively high coating film strength (hardness).

[0106] An epoxy resin that is semi-solid at 25°C refers to a highly viscous epoxy resin that has a viscosity of preferably 1,000 cP or more, more preferably 10,000 cP or more at 25°C when the epoxy resin has a solid content of 100%.

[0107] As the epoxy resin, commercially available products can be used. Examples of commercially available products that are liquid at room temperature (5 to 35°C, JIS Z 8703; the same applies below) include "Epotohto YD-128" (trade name, manufactured by Nippon Steel & Sumitomo Metal Corporation, epoxy equivalent 184 to 194, viscosity 12,000 to 15,000 cPs / 25°C), "jER828" (trade name, manufactured by Mitsubishi Chemical Corporation, epoxy equivalent 180 to 190, viscosity 12,000 to 15,000 cPs / 25°C), "Epotohto YDF-170" (trade name, manufactured by Nippon Steel & Sumitomo Metal Corporation, epoxy equivalent 160 to 180, viscosity 2,000 to 5,000 cPs / 25°C), and "Frep 60" (trade name, manufactured by Toray Thiokol Co., Ltd., epoxy equivalent approximately 280, viscosity approximately 17,000 cPs / 25°C).

[0108] Examples of commercially available products that are semi-solid at room temperature include "E-834-85X(T)" (trade name, manufactured by Ohtake Meishin Chemical Co., Ltd., epoxy equivalent weight: 230 to 270), "jER834" (trade name, manufactured by Mitsubishi Chemical Corporation, epoxy equivalent weight: 230 to 270), "Epotohto YD134" (trade name, manufactured by Nippon Steel & Sumitomo Metal Corporation, epoxy equivalent weight: 230 to 270), "Epotohto YD-172" (trade name, manufactured by Nippon Steel & Sumitomo Metal Corporation, epoxy equivalent weight: 600 to 700), and "Epicron-5300-70" (trade name, manufactured by DIC Corporation, epoxy equivalent weight: 450 to 500).

[0109] An example of a commercially available product that is solid at room temperature is "jER1001-75X" (trade name, manufactured by Mitsubishi Chemical Corporation, epoxy equivalent weight 450 to 500).

[0110] The epoxy equivalent of the epoxy resin is preferably 160-700, more preferably 160-500. The viscosity of the epoxy resin is preferably 500 to 20,000 cPs / 25°C, and more preferably 500 to 18,000 cPs / 25°C. When the epoxy equivalent and viscosity of the epoxy resin are within the above ranges, a composition S1 with excellent workability can be easily obtained, and a coating film S1 with excellent strength and excellent adhesion to the antifouling coating film A1 can be easily formed, which is preferable.

[0111] It has been found that when forming a tie coat T1 or an antifouling coating film A2 on a coating film S1, the adhesion between the coating film S1 and the tie coat T1 or the antifouling coating film A2 tends to decrease as the epoxy equivalent of the epoxy resin used in the composition S1 increases. Therefore, when forming a tie coat T1 or an antifouling coating film A2 on a coating film S1, the epoxy equivalent of the epoxy resin is preferably 500 or less, more preferably 160 to 490, and even more preferably 170 to 480. The epoxy equivalent is calculated based on JIS K 7236:2001. When two or more epoxy resins are blended into composition S1, the epoxy equivalent of the epoxy resins is the epoxy equivalent of the two or more epoxy resins as a whole. Specifically, when y parts by mass (solid content) of epoxy resin e1, whose solid content epoxy equivalent is a, and z parts by mass (solid content) of epoxy resin e2, whose solid content epoxy equivalent is b, are blended, the epoxy equivalent of the epoxy resins is calculated as a×y / (y+z)+b×z / (y+z).

[0112] The content of the solid content of the epoxy resin is preferably 0.1 to 50 mass %, more preferably 5 to 50 mass %, and even more preferably 10 to 40 mass %, relative to 100 mass % of the solid content of the composition S1. When the epoxy resin content is within the above range, a composition S1 having excellent coating workability can be easily obtained, and a coating film S1 having excellent leveling properties, adhesion to the antifouling coating film A1, toughness, and flexibility can be easily formed.

[0113] The "solid content" of composition S1 and each raw material used in composition S1 refers to the mass excluding volatile components. The solid content of each raw material containing volatile components such as solvents refers to the residue when the volatile components such as solvents are evaporated by drying in a hot air dryer at 105°C for 3 hours. The solid content of composition S1 is a value calculated in accordance with JIS K 5601-1-2:2008 by weighing out 1±0.1 g of this composition (in the case of the two-component composition, the composition immediately after mixing the main component and the hardener component) onto a flat-bottom dish, spreading it evenly using a wire of known mass, leaving it at 23°C for 24 hours, drying it at 110°C for 1 hour under normal pressure, and then weighing the heating residue and the mass of the wire.

[0114] Furthermore, as described above, when (i) bisphenol A type and / or bisphenol F type epoxy resin and (ii) novolac type epoxy resin are used in combination, the ratio of use ((i):(ii)) is preferably 300:100 to 100:300, more preferably 200:100 to 100:200, and even more preferably 150:100 to 100:150 by mass, in order to facilitate the formation of a coating film S1 having sufficient strength without excessively high coating film strength (hardness).

[0115] [Amine-based curing agent] The amine curing agent is not particularly limited as long as it is an amine compound other than a tertiary amine (an amine compound having only a tertiary amino group), and examples thereof include amine compounds containing two or more amino groups in one molecule. Specific examples thereof include aliphatic amine curing agents, alicyclic amine curing agents, aromatic amine curing agents, aromatic aliphatic amine curing agents, and heterocyclic amine curing agents. The amine-based curing agent may be used alone or in combination of two or more kinds.

[0116] Examples of the aliphatic amine curing agent include alkyl monoamines, alkylene polyamines, polyalkylene polyamines, and alkylamino alkyl amines.

[0117] The alkylene polyamine may be, for example, a compound represented by the formula: "H2N-R 1 -NH2" (R 1 is a divalent hydrocarbon group having 1 to 12 carbon atoms. Specific examples thereof include methylenediamine, ethylenediamine, 1,2-diaminopropane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, and trimethylhexamethylenediamine.

[0118] Examples of the polyalkylene polyamine include those of the formula: "HN-(C m H 2m NH)n Specific examples of the compound include diethylenetriamine, dipropylenetriamine, triethylenetetramine, tripropylenetetramine, tetraethylenepentamine, tetrapropylenepentamine, pentaethylenehexamine, nonaethylenedecamine, bis(hexamethylene)triamine, and triethylene-bis(trimethylene)hexamine.

[0119] Examples of the alkylaminoalkylamine include those represented by the formula: 2 2N-(CH2) p -NH2" (R 2 are independently a hydrogen atom or an alkyl group having 1 to 8 carbon atoms (provided that at least one R 2 is an alkyl group having 1 to 8 carbon atoms, and p is an integer of 1 to 6. Specific examples thereof include dimethylaminoethylamine, diethylaminoethylamine, dibutylaminoethylamine, dimethylaminopropylamine, diethylaminopropylamine, dipropylaminopropylamine, dibutylaminopropylamine, and dimethylaminobutylamine.

[0120] Other aliphatic amine curing agents include, for example, tetra(aminomethyl)methane, tetrakis(2-aminoethylaminomethyl)methane, 1,3-bis(2'-aminoethylamino)propane, 2,2'-[ethylenebis(iminotrimethyleneimino)]bis(ethanamine), tris(2-aminoethyl)amine, bis(cyanoethyl)diethylenetriamine, and polyoxyalkylenepolyamines (particularly, diethylene glycol bis(3-aminopropyl)ether).

[0121] Examples of the alicyclic amine curing agent include cyclohexanediamine, diaminodicyclohexylmethane (particularly, 4,4'-methylenebiscyclohexylamine), 4,4'-isopropylidenebiscyclohexylamine, norbornanediamine, 2,4-di(4-aminocyclohexylmethyl)aniline, bis(aminomethyl)cyclohexane, isophoronediamine, and menthenediamine (MDA).

[0122] Examples of aromatic amine curing agents include aromatic polyamine compounds having two or more primary amino groups bonded to an aromatic ring such as a benzene ring or a naphthalene ring. More specific examples of the aromatic amine curing agent include phenylenediamine, naphthalenediamine, diaminodiphenylmethane, 2,2-bis(4-aminophenyl)propane, 4,4'-diaminodiphenyl ether, 4,4'-diaminobenzophenone, 4,4'-diaminodiphenyl sulfone, 2,2'-dimethyl-4,4'-diaminodiphenylmethane, 2,4'-diaminobiphenyl, 2,3'-dimethyl-4,4'-diaminobiphenyl, and 3,3'-dimethoxy-4,4'-diaminobiphenyl.

[0123] Examples of the aromatic aliphatic amine curing agent include bis(aminoalkyl)benzene and bis(aminoalkyl)naphthalene. More specific examples of the aromatic aliphatic amine curing agent include o-xylylenediamine, m-xylylenediamine (MXDA), p-xylylenediamine, bis(aminomethyl)naphthalene, and bis(aminoethyl)naphthalene.

[0124] Examples of heterocyclic amine curing agents include N-methylpiperazine, morpholine, 1,4-bis-(3-aminopropyl)piperazine, 1,4-diazacycloheptane, 1-(2'-aminoethylpiperazine), 1,4-bis(3-aminopropyl)piperazine, 1-[2'-(2''-aminoethylamino)ethyl]piperazine, 1,11-diazacycloeicosane, and 1,15-diazacyclooctacosane.

[0125] Further examples of the amine-based curing agent include amines (amine compounds) described in Japanese Patent Publication No. 49-48480, polyether diamines, modified products of the above-mentioned amine compounds, for example, fatty acid modified products such as polyamidoamines, amine adducts with epoxy compounds, Mannich-modified amines (e.g., Mannich-modified amines having a phenol-derived skeleton (phenalkamine, phenalkamide, etc.)), Michael adducts, ketimines, aldimines, and urethane modified products.

[0126] Among these, as the amine-based curing agent, Mannich-modified amines are preferred, and MXDA Mannich-modified amine is more preferred, from the viewpoints that a composition S1 having excellent curing speed, particularly low-temperature (5°C or less) curing ability, can be easily obtained, and a coating film S1 having an excellent balance of adhesion to the antifouling coating film A1 and strength can be easily formed.

[0127] As the MXDA Mannich-modified amine, for example, a Mannich-modified amine obtained by Mannich condensation using a phenol, an aldehyde, and m-xylylenediamine (MXDA) is preferred.

[0128] Examples of the phenols include phenols containing unsaturated substituents and phenols containing saturated substituents, and one or more of these may be used.

[0129] Examples of the unsaturated substituent-containing phenol include compounds that contain at least one monohydroxyphenyl group in the molecule and in which some of the hydrogen atoms in the phenyl group, i.e., 1 to 5 hydrogen atoms bonded to the phenyl group, have been substituted with unsaturated hydrocarbon groups. Examples of the unsaturated hydrocarbon group include an alkylene group having about 1 to 10 carbon atoms and a phenyl group containing an alkylene group having about 1 to 10 carbon atoms. Specific examples of such unsaturated substituent-containing phenols include cardanol, isopropenylphenol, diisopropenylphenol, butenylphenol, isobutenylphenol, cyclohexenylphenol, monostyrenated phenol (C6H5-CH=CH-C6H4-OH), and distyrenated phenol ((C6H5-CH=CH)2-C6H3-OH).

[0130] The saturated substituent-containing phenol may be monovalent or polyvalent, and may be mononuclear or polynuclear. Specific examples include monovalent mononuclear phenols such as phenol; divalent mononuclear phenols such as resorcinol and hydroquinone; divalent polynuclear phenols such as 1,5-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, and 2,6-dihydroxynaphthalene; alkylphenols (alkyl group carbon number: 1 to 10, preferably 1 to 5) such as methylphenol (o, m, p-cresol), ethylphenol, butylphenol, t-butylphenol, octylphenol, nonylphenol, dodecylphenol, and dinonylphenol; halogenated phenols such as chlorophenol; alkoxyphenols (alkoxy group carbon number: 1 to 10, preferably 1 to 5) such as methoxyphenol; bisphenol A; and bisphenol F. Among these, monovalent mononuclear phenols are preferred.

[0131] Examples of the aldehydes include formaldehyde, paraformaldehyde, and acetaldehyde, and one or more of these may be used.

[0132] In the Mannich condensation, for example, the phenols, aldehydes, and MXDA may theoretically be used in equimolar amounts, but typically, 0.5 to 2.5 moles of aldehydes and 0.5 to 2.5 moles of MXDA are used per mole of phenols, and the mixture is heated at a temperature of about 50 to 180° C. for about 3 to 12 hours. After completion of the reaction, the reaction product may be heated under reduced pressure to remove moisture and unreacted materials.

[0133] Among the MXDA Mannich-modified amines obtained by subjecting a phenol, an aldehyde, and MXDA to a Mannich condensation reaction, the Mannich-modified amine obtained by reacting cardanol, formaldehyde, and MXDA is preferred.

[0134] The amine value of the amine-based curing agent is preferably 100 to 500 mgKOH / g, more preferably 200 to 500 mgKOH / g, from the viewpoints that a composition S1 having excellent curing properties can be easily obtained and a coating film S1 having a good balance between coating film strength and adhesion to the antifouling coating film A1 can be easily formed. For the same reason, the active hydrogen equivalent of the amine curing agent is preferably 50-500, more preferably 80-400.

[0135] As the amine-based curing agent, commercially available products may be used, and examples of such commercially available products include Luckamide V6-221 (MXDA Mannich-modified amine, liquid, solid content 100% by mass, amine value 420 mgKOH / g) manufactured by DIC Corporation, and MAD-204(A) (MXDA Mannich-modified amine, solid, solid content 65% by mass, amine value 250 mgKOH / g) manufactured by Ohtake Meishin Chemical Co., Ltd.

[0136] Although it is not necessarily determined depending on the coating and curing conditions of composition S1, the viscosity of the amine-based curing agent measured with an E-type viscometer when the solid content is adjusted to 50 to 100 mass % is preferably 100 to 100,000 cPs / 25°C, more preferably 500 to 10,000 cPs / 25°C, from the viewpoint of easily obtaining composition S1 that is excellent in handleability and coatability, when the solid content is adjusted to 50 to 100 mass %.

[0137] As the amine-based curing agent, it is preferable to use both in combination, since the use of a curing agent (I) that is solid at 25°C improves the initial curing properties of the resulting composition S1, and the use of a curing agent (II) that is liquid at 25°C makes it easy to form a coating film S1 with high initial strength. The ratio of the amounts of the curing agents (I) and (II) used ((I):(II), solid content mass ratio) is preferably 100:0.1 to 0.1:100, and more preferably 100:10 to 10:100. When the ratio of the amounts of curing agents (I) and (II) used is within the above range, a composition S1 having the desired curability can be easily obtained, and a coating film S1 having the desired strength and durability can be easily formed.

[0138] From the viewpoints of easily obtaining a composition S1 with excellent curing properties and easily forming a coating film S1 that has a good balance between coating film strength and adhesion to the antifouling coating film A1 and topcoat coating films (tie coat T1 and antifouling coating film A2), it is preferable to use the amine-based curing agent in an amount such that the reaction ratio calculated by the following formula is preferably 0.3 to 1.0, more preferably 0.5 to 1.0. Reactivity ratio = {(amount of solid content of amine curing agent (B) / active hydrogen equivalent of solid content of amine curing agent (B)) + (amount of solid content of component reactive with epoxy resin (A) / functional group equivalent of solid content of component reactive with epoxy resin (A))} / {(amount of solid content of epoxy resin (A) / epoxy equivalent of solid content of epoxy resin (A)) + (amount of solid content of component reactive with amine curing agent (B) / functional group equivalent of solid content of component reactive with amine curing agent (B))}

[0139] Here, examples of the "component reactive with the epoxy resin (A)" in the above formula include the following silane coupling agents, and examples of the "component reactive with the amine curing agent (B)" include the following silane coupling agents. As the silane coupling agent, a silane coupling agent having an amino group or an epoxy group as a reactive group can be used. Therefore, depending on the type of the reactive group, it is necessary to determine whether the silane coupling agent is reactive with the epoxy resin (A) or the amine curing agent (B), and then calculate the reactivity ratio. For example, when two or more epoxy resins are blended into composition S1, specifically, when y parts by mass (solid content) of epoxy resin e1 having an epoxy equivalent of a solid content of a and z parts by mass (solid content) of epoxy resin e2 having an epoxy equivalent of b solid content of b are blended, the above "(blending amount of solid content of epoxy resin (A) / epoxy equivalent of solid content of epoxy resin (A))" is calculated as y / a+z / b. The same applies to other components.

[0140] The "functional group equivalent" of each component means the mass (g) per 1 mol of functional group obtained by dividing the mass of 1 mol of that component by the number of moles of the functional group contained therein.

[0141] [Pigment] The pigment is not particularly limited as long as it is a pigment other than gypsum, which will be described below. Examples of the pigment include extender pigments, color pigments, and anti-rust pigments, and may be either organic or inorganic. One type of pigment may be used, or two or more types may be used.

[0142] The extender pigment has a small refractive index and is transparent when mixed with oil or varnish, so that it does not obscure the surface to be coated. When composition S1 contains an extender pigment, it is preferable in that it can easily form a coating film S1 that has excellent coating film properties such as crack resistance. One type of extender pigment may be used, or two or more types may be used.

[0143] Examples of the extender pigment include zinc oxide, talc, silica, mica, clay, potassium feldspar, glass flake, calcium carbonate also used as an anti-settling agent, kaolin, alumina white, white carbon also used as a matting agent, aluminum hydroxide, magnesium carbonate, barium carbonate, and barium sulfate (e.g., barite powder). Among these, at least one pigment selected from the group consisting of talc, silica, mica, clay, calcium carbonate, kaolin, barium sulfate, and potassium feldspar is preferred.

[0144] Composition S1 preferably contains a flat pigment such as talc, mica or glass flake as an extender pigment, in order to reduce internal stress in the coating film S1 to be formed and improve adhesion to the antifouling coating film A1. Talc and mica are preferred as the flat pigments, as they are inexpensive, readily available, and can easily form a coating film S1 that exhibits the above-mentioned effects.

[0145] When composition S1 contains an extender pigment, the content thereof is preferably such that the PVC falls within the following range, specifically, preferably 0.1 to 500 parts by mass, more preferably 50 to 400 parts by mass, per 100 parts by mass of the epoxy resin. Furthermore, when the composition S1 contains a flat pigment, the content thereof is preferably 0.1 to 300 parts by mass, more preferably 10 to 200 parts by mass, per 100 parts by mass of the epoxy resin, from the viewpoint of easily forming a coating film S1 that has excellent adhesion to the antifouling coating film A1, etc.

[0146] As the color pigment, various conventionally known organic and inorganic color pigments can be used. Examples of organic pigments include naphthol red and phthalocyanine blue. Examples of inorganic pigments include carbon black, red iron oxide, titanium dioxide, yellow iron oxide, and aluminum powder. One type of color pigment may be used, or two or more types may be used.

[0147] When composition S1 contains a color pigment, the content thereof is preferably an amount such that the PVC falls within the following range, specifically, preferably 0.01 to 100 parts by mass, more preferably 0.01 to 70 parts by mass, per 100 parts by mass of the epoxy resin.

[0148] Examples of the rust-preventive pigment include molybdic acid-based, phosphoric acid-based, boric acid-based, ferrite-based, and lead acid-based rust-preventive pigments. The anti-rust pigment may be used alone or in combination of two or more.

[0149] The pigment volume concentration (PVC) in the composition S1 is preferably 25 to 50%, more preferably 30 to 48%. When the PVC is within the above range, a composition S1 having excellent film-forming properties and coating workability can be easily obtained, and a coating film S1 having excellent adhesion to the antifouling coating film A1 due to stress relaxation and suppressed blisters and cracks can be easily formed.

[0150] The PVC in the composition S1 refers to the total volume concentration of the pigment and gypsum in the composition S1 relative to the volume of the solid content of the composition S1. Specifically, the PVC can be calculated by the following formula: PVC [%] in composition S1 = total volume of all pigments and gypsum in composition S1 × 100 / volume of solids in composition S1

[0151] The volume of the solid content of the composition S1 can be calculated from the mass and true density of the solid content of the composition S1. The mass and true density of the solid content may be measured values ​​or values ​​calculated from the raw materials used. The volume of the pigment and gypsum can be calculated from the mass and true density of the pigment and gypsum used. The mass and true density of the pigment and gypsum may be measured values ​​or values ​​calculated from the raw materials used. For example, the volume can be calculated by separating the pigment and gypsum from other components from the solid content of composition S1 and measuring the mass and true density of the separated pigment and gypsum.

[0152] [Optional ingredients] The composition S1 may contain optional components other than the epoxy resin, amine-based curing agent, and pigment, as long as the effects of the present invention are not impaired. Examples of the optional components include gypsum; hardening accelerators; plasticizers; (pigment) dispersants; anti-sagging agents; anti-settling agents; solvents; reactive diluents; adhesion enhancers such as silane coupling agents; thermoplastic resins (e.g., vinyl (co)polymers [including vinyl chloride resins], excluding petroleum resins); dehydrating agents (stabilizers); antifouling agents; cement; fibrous fillers such as rock wool and glass fiber; other coating film-forming components; and dyes.

[0153] <plaster> When the composition S1 contains gypsum, a coating film S1 having excellent water resistance, saltwater resistance, and corrosion resistance can be easily formed. One type of gypsum may be used, or two or more types may be used.

[0154] Examples of the gypsum include crystalline gypsum (CaSO4·2H2O), hemihydrate gypsum (CaSO4·0.5H2O), and anhydrous gypsum (CaSO4). Among these, hemihydrate gypsum and / or anhydrous gypsum are preferred. These may be natural or artificial. The form is not particularly limited, but powder form is preferred.

[0155] Anhydrous gypsum and hemihydrate gypsum have the property of hardening when they absorb moisture and retaining it. Therefore, it is thought that the coating film S1 containing anhydrous gypsum or hemihydrate retains moisture and relieves internal stress in the coating film through its plasticizing effect, thereby improving adhesion to the antifouling coating film A1.

[0156] There are α-type and β-type hemihydrate gypsum, but the β-type is preferred from the viewpoint of the strength of the coating film S1 to be formed. An example of the hemihydrate gypsum is "FT-2" (average particle size: 15 μm) manufactured by Noritake Co., Ltd.

[0157] Anhydrous gypsum includes, but is not limited to, types I, II and III. An example of anhydrous gypsum is "AS Gypsum" manufactured by San-Esu Gypsum Co., Ltd.

[0158] When composition S1 contains gypsum, the content thereof is preferably such that the PVC falls within the above-mentioned range, and specifically, the content is preferably 5 to 100 parts by mass, more preferably 5 to 50 parts by mass, per 100 parts by mass of the epoxy resin, from the viewpoint of easily forming a coating film S1 that has excellent adhesion to the antifouling coating film A1 and is inhibited from cracking.

[0159] <Curing accelerator> Composition S1 preferably contains a curing accelerator to further improve the curing rate and low-temperature curing properties. The curing accelerator may be used alone or in combination of two or more.

[0160] The curing accelerator may be any conventionally known curing accelerator used in paints, but tertiary amines, acrylic esters, etc. are preferred because they can easily produce a composition S1 that has excellent curing speed and low-temperature (5°C or below) curing properties.

[0161] The tertiary amine is not particularly limited, but examples thereof include triethanolamine, dialkylaminoethanol {[CH3(CH2) n ]NCHCHOH}, triethylenediamine[1,4-diazacyclo(2,2,2)octane], and 2,4,6-tri(dimethylaminomethyl)phenol (e.g., trade name "Versamin EH30" manufactured by BASF Japan Ltd., trade name "Ancamin K-54" manufactured by Air Products Japan Ltd.). Among these, 2,4,6-tri(dimethylaminomethyl)phenol is preferred.

[0162] The acrylic acid ester is not particularly limited, but is preferably a polyfunctional acrylic acid ester, and examples of commercially available products thereof include polyfunctional acrylic ester (trade name "M-Cure 400", manufactured by Sartomer Corporation).

[0163] When composition S1 contains a curing accelerator, the content thereof is preferably 0.01 to 30 parts by mass, more preferably 0.01 to 15 parts by mass, relative to 100 parts by mass of the epoxy resin, from the viewpoint that composition S1 having excellent curing speed and low-temperature curing properties can be easily obtained.

[0164] <Plasticizer> It is preferable that the composition S1 contains a plasticizer, since this allows the viscosity of the composition S1 to be easily adjusted, has the effect of alleviating internal stress in the coating film S1 to be formed, and allows the coating film S1 to be easily formed with excellent adhesion to the antifouling coating film A1 and excellent coating film strength. One type of plasticizer may be used, or two or more types may be used.

[0165] Examples of plasticizers include phosphate esters (e.g., tricresyl phosphate [TCP]), chlorinated paraffin (chlorinated paraffin), petroleum resins, ketone resins, polyvinyl ethyl ether, and dialkyl phthalates. Among these, phosphate esters are preferred.

[0166] When composition S1 contains a plasticizer, the content thereof is preferably 0.1 to 40 parts by mass, more preferably 0.1 to 20 parts by mass, per 100 parts by mass of the epoxy resin, from the viewpoint of facilitating the formation of a coating film S1 that has excellent adhesion to the antifouling coating film A1, etc.

[0167] <(Pigment) Dispersant> As the (pigment) dispersant, various conventionally known organic and inorganic dispersants can be used. Examples of organic dispersants include aliphatic amines or organic acids (for example, "Duomin TDO" manufactured by LION Corporation, and "DisperBYK101" manufactured by BYK CHEMIE). The (pigment) dispersant may be used alone or in combination of two or more kinds.

[0168] When the composition S1 contains a (pigment) dispersant, the content thereof is preferably 0.01 to 20 parts by mass, and more preferably 0.01 to 10 parts by mass, relative to 100 parts by mass of the epoxy resin.

[0169] <Anti-sagging agent> It is preferable that the composition S1 contains an anti-sagging agent, since it is possible to adjust the anti-sagging properties during application. One type of anti-sagging agent may be used, or two or more types may be used.

[0170] Examples of the anti-sagging agent include amide wax compounds, hydrogenated castor oil wax compounds, polyamide wax compounds, inorganic bentonite compounds, synthetic finely powdered silica, and mixtures thereof, with polyamide wax and synthetic finely powdered silica being preferred. As the anti-sagging agent, commercially available products may be used, and examples of such commercially available products include "Disparlon 6650" and "Disparlon A630-20XC" manufactured by Kusumoto Chemicals Co., Ltd., "ASAT-250F" manufactured by Ito Oil Milling Co., Ltd., and "Benton 27" manufactured by Elementis Specialties, Inc.

[0171] When the composition S1 contains an anti-sagging agent, the content thereof is preferably 0.1 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, relative to 100 parts by mass of the epoxy resin.

[0172] <Anti-settling agent> If composition S1 contains an anti-settling agent, it is possible to reduce precipitation that may occur during storage of composition S1, and it is preferable in that it is possible to improve the stirrability of composition S1. The anti-settling agent may be used alone or in combination of two or more kinds.

[0173] Examples of the anti-settling agent include organic clay-based amine salts of Al, Ca or Zn, polyethylene wax, and oxidized polyethylene wax, and among these, oxidized polyethylene wax is preferred. As the anti-settling agent, commercially available products may be used, and examples of such commercially available products include "Disparlon 4200-20X" manufactured by Kusumoto Chemicals Co., Ltd.

[0174] When the composition S1 contains an anti-settling agent, the content thereof is preferably 0.1 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, relative to 100 parts by mass of the epoxy resin.

[0175] <solvent> As the solvent, conventionally known solvents with a wide range of boiling points can be used. Specific examples of the solvent include aliphatic solvents such as turpentine; aromatic solvents such as toluene and xylene; alcohol solvents such as isopropyl alcohol, n-butyl alcohol, and isobutyl alcohol; ester solvents such as ethyl acetate and butyl acetate; ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, and methyl amyl ketone; and ether or ether ester solvents such as ethylene glycol monomethyl ether, ethylene glycol monobutyl ether (butyl cellosolve), propylene glycol monomethyl ether (PGM), and propylene glycol monomethyl ether acetate. Of these, xylene, n-butyl alcohol, methyl isobutyl ketone, and propylene glycol monomethyl ether are preferred. The solvent may be used alone or in combination of two or more.

[0176] When composition S1 contains a solvent, the content thereof is not particularly limited, but in consideration of coating properties, etc., it is usually preferably 0.1 to 80 mass %, more preferably 0.1 to 60 mass %, relative to 100 mass % of composition S1.

[0177] <Silane coupling agent> It is preferable that the composition S1 contains a silane coupling agent, since the use of a silane coupling agent not only further improves the adhesion of the coating film S1 to the antifouling coating film A1, but also improves the corrosion resistance of the coating film S1 to be formed. The silane coupling agent may be used alone or in combination of two or more.

[0178] The silane coupling agent is not particularly limited, and any conventionally known compound can be used, but it is preferable that the silane coupling agent is a compound that has at least two functional groups in the same molecule and can contribute to improving adhesion to the substrate and reducing the viscosity of the composition S1.

[0179] The silane coupling agent is, for example, a compound represented by the formula: X-SiMe n Y 3-n" [n is 0 or 1, X is a functional group capable of reacting with an organic substance (e.g., an amino group, a vinyl group, an epoxy group, a mercapto group, a halogeno group, a group in which a hydrocarbon group is partially substituted with any of these groups, or a group in which a hydrocarbon group is partially substituted with an ether bond or the like and is partially substituted with any of these groups), Me is a methyl group, and Y is a hydrolyzable group (e.g., an alkoxy group such as a methoxy group or an ethoxy group).] is preferred.

[0180] Among the above-mentioned silane coupling agents, an epoxy group-containing silane coupling agent is preferred, in which X is an epoxy group, a group in which a hydrocarbon group is partly substituted with an epoxy group, or a group in which a hydrocarbon group is partly substituted with an ether bond or the like and partly substituted with an epoxy group.

[0181] Commercially available silane coupling agents may be used, such as 3-glycidoxypropyltrimethoxysilane "KBM-403" (manufactured by Shin-Etsu Chemical Co., Ltd.) and "Sila-Ace S-510" (manufactured by JNC Corporation).

[0182] When composition S1 contains a silane coupling agent, the content thereof is preferably 0.1 to 10 mass %, more preferably 0.3 to 5 mass %, relative to 100 mass % of the solid content of composition S1, from the viewpoints of being able to reduce the viscosity of composition S1, improving coating workability, and facilitating the formation of a coating film S1 that has excellent adhesion to the antifouling coating film A1.

[0183] <Base material> The substrate with this multilayer coating film can maintain the antifouling properties of substrates exposed to water (oceans, rivers, lakes, etc.) for a long period of time in a wide range of industrial fields such as ships, fisheries, and underwater structures. Examples of such substrates include ships (hull shells for large steel ships such as container ships and tankers, fishing boats, FRP boats, wooden boats, yachts, etc., particularly the waterline to bottom portions, and new ships or repaired ships of these), fishing materials (ropes, fishing nets, fishing gear, floats, buoys, etc.), underwater structures (oil pipelines, water conveyance pipes, circulating water pipes, water supply and drainage pipes for factories and thermal and nuclear power plants, undersea cables, seawater utilization equipment (seawater pumps, etc.), megafloats, coastal roads, undersea tunnels, port facilities, various underwater civil engineering structures in canals and waterways, etc.), items used underwater and on the water (underwater lights, underwater sensors, oxygen cylinders, etc.), and torpedoes. Among these, substrates selected from the group consisting of ships, underwater structures, and fishing materials are preferred, substrates selected from the group consisting of ships and underwater structures are more preferred, and ships are even more preferred.

[0184] The material of the substrate is not particularly limited, and when the substrate is a ship or the like, examples thereof include steel (iron, steel, ferroalloy, carbon steel, mild steel, alloy steel, etc.), non-ferrous metals (zinc, aluminum, copper, brass, zinc plating, zinc thermal spraying, etc.), stainless steel (SUS304, SUS410, etc.), wood, and FRP; when the substrate is a fishing net or the like, examples thereof include natural or synthetic fibers; and when the substrate is a float, buoy, etc., examples thereof include synthetic resins.

[0185] The substrate on which the antifouling coating film A1 of the present laminated coating film-coated substrate is formed is preferably a substrate that has been treated with other treatment agents such as anti-rust agents, or a substrate on which an undercoat coating film (e.g., a primer coating film or an anti-corrosion coating film) has been formed.

[0186] Examples of compositions for forming the undercoat film include zinc-based shop primers, epoxy resin-based zinc-rich primers, and epoxy resin-based anticorrosive paints, with epoxy resin-based anticorrosive paints being preferred. The epoxy resin-based anticorrosive coating typically contains an epoxy resin as the resin component and an amine-based curing agent for the epoxy resin, and may also contain, as necessary, thermoplastic resins (e.g., vinyl copolymers), rosins, plasticizers, extender pigments, coloring pigments, rust-preventive pigments, solvents, curing accelerators, coupling agents, anti-sagging agents, anti-settling agents, and the like. The composition S1 may also be used as the composition for forming the undercoat film.

[0187] In addition, in order to improve the adhesion between the substrate and the primer coating film, the surface of the substrate may be treated in advance by sandblasting, friction, degreasing to remove oil and dust, or the like, before the primer coating film is formed.

[0188] <Organopolysiloxane-based antifouling coating film A2> The substrate with this multilayer coating film preferably has an organopolysiloxane-based antifouling coating film A2 on the outermost surface of the substrate (the outermost surface opposite the substrate) in order to inhibit the attachment and proliferation of various aquatic organisms. The antifouling coating film A2 can also be called a new antifouling coating film, as it is an antifouling coating film formed from an antifouling paint that is newly applied to the antifouling coating film A1 (old antifouling coating film A1).

[0189] The antifouling coating film A2 is preferably a coating film formed from a composition containing a curable polyorganosiloxane and a slip agent.

[0190] The film thickness of the antifouling coating film A2 is not particularly limited, but from the viewpoint of easily forming an antifouling coating film that has excellent long-term antifouling properties, it is preferably 5 μm or more, more preferably 10 μm or more, even more preferably 50 μm or more, and is preferably 1,000 μm or less, more preferably 500 μm or less, even more preferably 300 μm or less.

[0191] [Composition A2] Composition A2 preferably comprises a curable polyorganosiloxane and a slip agent. The antifouling coating composition A1 may be used as composition A2.

[0192] [Curable polyorganosiloxane] When composition A2 contains a curable polyorganosiloxane, an antifouling coating film A2 having excellent antifouling properties can be easily formed. The curable polyorganosiloxane may be used alone or in combination of two or more.

[0193] As curable polyorganosiloxane, for example, can be mentioned the compound that has the main chain with polyorganosiloxane structure and reactive group, and this reactive group reacts with each other, or this reactive group reacts with the reactive group of the organic silicon crosslinking agent described later, thereby form three-dimensional crosslinked structure and harden.In addition, can react with the silane coupling agent described later.

[0194] Examples of the polyorganosiloxane structure include a polydimethylsiloxane structure and a polymethylphenylsiloxane structure, and among these, a polydimethylsiloxane structure is preferred, in which alkylene groups, polyoxyalkylene groups, etc. may be present in a block form. Furthermore, as the linking site between the main chain and the reactive group, for example, an alkylene group or a polyoxyalkylene group may be present.

[0195] Specific examples of the reactive group include an addition reactive group or a condensation reactive group, and a condensation reactive group is preferred because it is less affected by curing inhibitors in the curing reaction and a stable reaction rate can be obtained. Examples of the condensation reactive group include a silanol group, an oximesilyl group, an acyloxysilyl group, an alkoxysilyl group, an alkenyloxysilyl group, an aminosilyl group, and an amidosilyl group. Of these, a silanol group, an oximesilyl group, an acyloxysilyl group, an alkoxysilyl group, and an alkenyloxysilyl group are preferred, a silanol group, an oximesilyl group, an alkoxysilyl group, and an alkenyloxysilyl group are more preferred, and a silanol group and an oximesilyl group are even more preferred.

[0196] The oxime group is preferably an oxime group having 1 to 10 carbon atoms, more preferably a dimethyl ketoxime group, a methyl ethyl ketoxime group, a diethyl ketoxime group, a methyl isopropyl ketoxime group, or a methyl isobutyl ketoxime group, and even more preferably a methyl ethyl ketoxime group or a methyl isobutyl ketoxime group.

[0197] The alkoxy group is preferably an alkoxy group having 1 to 6 carbon atoms, more preferably a methoxy group, an ethoxy group, a propoxy group, or a butoxy group, still more preferably a methoxy group or an ethoxy group, and particularly preferably a methoxy group.

[0198] The oxime group or alkoxy group preferably has two or more oxime groups or alkoxy groups bonded to one silicon atom as the condensation reactive group.

[0199] The position of the reactive group may be directly bonded to a silicon atom of the main chain, in a side chain, at both ends of the main chain, or at one end of the main chain, with both ends of the main chain being preferred.

[0200] The curable polyorganosiloxane is preferably a curable polyorganosiloxane having a reactive group, and specific examples thereof include silanol group-containing polyorganosiloxanes, oximesilyl group-containing polyorganosiloxanes, alkoxy group-containing polyorganosiloxanes, and enol silyl ether group-containing polyorganosiloxanes. Silanol group-containing polyorganosiloxanes, oximesilyl group-containing polyorganosiloxanes, and alkoxy group-containing polyorganosiloxanes are preferred, and silanol group-containing polyorganosiloxanes and oximesilyl group-containing polyorganosiloxanes are more preferred.

[0201] The curable polyorganosiloxane having the reactive group is preferably one that forms a silicone rubber when cured, and for example, a compound represented by the following formula (A1) is preferred.

[0202] [ka] [In formula (A1), R 11 and R 13 each independently represents a hydrogen atom, an alkyl group having 1 to 16 carbon atoms, an alkenyl group having 2 to 16 carbon atoms, an aryl group having 6 to 16 carbon atoms, an aralkyl group having 7 to 16 carbon atoms, or a halogenated alkyl group having 1 to 16 carbon atoms; R 12 Each independently represents a hydroxy group or a hydrolyzable group. 11 ~R 13 may be the same or different, r represents an integer of 1 to 3, and p represents an integer of 10 to 10,000.

[0203] R 11 and R 13 The alkyl group in the formula (I) is a group having 1 to 16 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, and a heptyl group.

[0204] R 11 and R 13 The alkenyl group in the formula (I) is a group having 2 to 16 carbon atoms, and examples thereof include a vinyl group, an allyl group, a propenyl group, an isopropenyl group, a butenyl group, an isobutenyl group, a pentenyl group, a heptenyl group, a hexenyl group, and a cyclohexenyl group.

[0205] R 11 and R 13 The aryl group in the formula (I) is a group having 6 to 16 carbon atoms, which may have a substituent such as an alkyl group on the aromatic ring, and examples thereof include a phenyl group, a tolyl group (methylphenyl group), a xylyl group (dimethylphenyl group), and a naphthyl group.

[0206] R 11 and R 13 The aralkyl group in the formula (I) is a group having 7 to 16 carbon atoms, and examples thereof include a benzyl group, a 2-phenylethyl group, a 2-naphthylethyl group, and a diphenylmethyl group.

[0207] R 11 and R 13The halogenated alkyl group in the formula (I) is a group having 1 to 16 carbon atoms, and examples thereof include groups in which some or all of the hydrogen atoms contained in the alkyl group have been substituted with halogen atoms such as fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

[0208] Among these, R 11 is preferably a hydrogen atom, an alkyl group, an alkenyl group, or an aryl group, more preferably a methyl group, an ethyl group, a vinyl group, or a phenyl group, and even more preferably a methyl group or a vinyl group.

[0209] Also, R 13 is preferably a hydrogen atom, an alkyl group, an alkenyl group, or an aryl group, more preferably a methyl group, an ethyl group, a vinyl group, or a phenyl group, further preferably a methyl group, an ethyl group, or a phenyl group, and particularly preferably a methyl group or a phenyl group.

[0210] R 12 Examples of the hydrolyzable group in the formula (I) include an oxime group, an acyloxy group, an alkoxy group, an alkenyloxy group, an amino group, an amido group, and an aminooxy group.

[0211] R 12 The oxime group in the formula (I) is preferably an oxime group having a total of 1 to 10 carbon atoms, and examples thereof include a dimethyl ketoxime group, a methyl ethyl ketoxime group, a diethyl ketoxime group, a methyl isopropyl ketoxime group, and a methyl isobutyl ketoxime group.

[0212] R 12 The acyloxy group (RC(=O)O-) in the formula (I) is preferably an aliphatic acyloxy group having a total of 2 to 10 carbon atoms or an aromatic acyloxy group having a total of 7 to 12 carbon atoms, and examples thereof include an acetoxy group, a propionyloxy group, a butyryloxy group, and a benzoyloxy group.

[0213] R 12 The alkoxy group in R is preferably an alkoxy group having a total carbon number of 1 to 10. 12In the alkoxy group represented by the formula (I), one or more oxygen atoms may be present between one or more carbon atoms. R 12 Specific examples of the alkoxy group in the formula (I) include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a methoxyethoxy group, and an ethoxyethoxy group.

[0214] R 12 The alkenyloxy group in the formula (I) is preferably an alkenyloxy group having 3 to 10 carbon atoms, and examples thereof include an isopropenyloxy group, an isobutenyloxy group, and a 1-ethyl-2-methylvinyloxy group.

[0215] R 12 The amino group in is preferably an amino group having 1 to 10 carbon atoms, and examples thereof include an N-methylamino group, an N-ethylamino group, an N-propylamino group, an N-butylamino group, an N,N-dimethylamino group, an N,N-diethylamino group, and a cyclohexylamino group.

[0216] R 12 The amide group in the formula (I) is preferably an amide group having a total of 2 to 10 carbon atoms, and examples thereof include an N-methylacetamide group, an N-ethylacetamide group, and an N-methylbenzamide group.

[0217] R 12 The aminooxy group in the formula (I) is preferably an aminooxy group having a total of 2 to 10 carbon atoms, and examples thereof include an N,N-dimethylaminooxy group and an N,N-diethylaminooxy group.

[0218] Among these, R is the most preferred because it can easily form an antifouling coating film A2 that has excellent curing properties and antifouling properties. 12 is preferably a hydroxy group, an oxime group, or an alkoxy group, more preferably a hydroxy group or an oxime group, and further preferably a hydroxy group, a methyl ethyl ketoxime group, or a methyl isobutyl ketoxime group.

[0219] R 12 is a hydroxy group, r is preferably 1, and R12 When is a substituent other than a hydroxy group, r is preferably 2.

[0220] p is preferably 100 to 1,000, and is preferably adjusted appropriately so as to satisfy the following weight average molecular weight. Note that p is -(SiR 13 2-O)-mean repeat number.

[0221] The weight average molecular weight (Mw) of the curable polyorganosiloxane is preferably 500 or more, more preferably 5,000 or more, even more preferably 10,000 or more, still more preferably 15,000 or more, and particularly preferably 20,000 or more, from the viewpoint of improving workability during the production of composition A2, the coating workability and curing properties of composition A2, and the strength of the antifouling coating film A2 formed, and is preferably 1,000,000 or less, more preferably 100,000 or less, even more preferably 50,000 or less, and particularly preferably 40,000 or less. The "weight average molecular weight (Mw)" and the "number average molecular weight (Mn)" described below of each raw material used in composition A2 are measured using GPC and calculated by converting them into standard polystyrene of known molecular weight.

[0222] The viscosity of the curable polyorganosiloxane at 25°C is preferably 20 mPa·s or more, more preferably 100 mPa·s or more, even more preferably 500 mPa·s or more, and particularly preferably 1,000 mPa·s or more, from the viewpoint of improving workability during the production of composition A2, the coating workability and curability of composition A2, and the strength of the antifouling coating film A2 formed, and is preferably 100,000 mPa·s or less, more preferably 10,000 mPa·s or less, even more preferably 5,000 mPa·s or less, and particularly preferably 3,000 mPa·s or less. In this specification, the viscosity of the curable polyorganosiloxane at 25° C. is the viscosity measured using a B-type rotational viscometer (for example, Model BM, manufactured by Tokyo Keiki Co., Ltd.).

[0223] As the curable polyorganosiloxane, a commercially available product may be used, and examples of such commercially available products include "DMS-S35" manufactured by GELEST Co., Ltd. and "KE-445" manufactured by Shin-Etsu Chemical Co., Ltd. In addition, as the curable polyorganosiloxane, a compound described in JP-A-2001-139816 can also be used.

[0224] The content of the curable polyorganosiloxane in composition A2 is preferably 25% by mass or more, more preferably 30% by mass or more, and even more preferably 35% by mass or more, from the viewpoint of being able to easily form an antifouling coating film A2 having excellent antifouling properties and strength, and is preferably 90% by mass or less, more preferably 70% by mass or less, and even more preferably 60% by mass or less. For the same reason, the content of curable polyorganosiloxane in 100% by mass of the solid content of composition A2 is preferably 45% by mass or more, more preferably 50% by mass or more, even more preferably 55% by mass or more, and preferably 85% by mass or less, more preferably 80% by mass or less, even more preferably 75% by mass or less.

[0225] The "solid content" of each raw material used in composition A2 refers to the components excluding the organic solvent described below and the volatile components contained in each raw material, and the "solid content of composition A2" refers to the solid content obtained by drying composition A2 in a hot air dryer at 125°C for 1 hour.

[0226] <Slip agent> Composition A2 may contain a slipping agent, which allows for the easy production of a composition A2 with excellent coating workability and antifouling properties, etc. Furthermore, composition A2 containing a slipping agent can impart slipping properties to the antifouling coating film A2 formed, thereby improving the ability to inhibit adhesion of aquatic organisms (antifouling properties). The slipping agent may be used alone or in combination of two or more.

[0227] The slipping agent preferably has fluidity at 25°C, and more preferably is liquid. The use of a slipping agent with fluidity is thought to increase the mobility within the antifouling coating film A2, thereby enhancing the effect of imparting slipperiness to the surface of the antifouling coating film A2. Furthermore, the use of a slipping agent with fluidity can reduce the viscosity of the resulting composition A2, improving its coatability.

[0228] When composition A2 contains a slipping agent, the solids content thereof is preferably 1% by mass or more, more preferably 3% by mass or more, even more preferably 5% by mass or more, particularly preferably 10% by mass or more, relative to 100% by mass of the solids content of composition A2, from the viewpoint of enabling easy formation of an antifouling coating film A2 that has excellent formability and antifouling properties, and is preferably 40% by mass or less, more preferably 30% by mass or less, even more preferably 25% by mass or less, and even more preferably 20% by mass or less.

[0229] The slipping agent is preferably one or more selected from oils and polymers having a hydrophilic group. Examples of the oils include silicone oil, paraffin oil, and fats and oils, and among these, silicone oil is preferred. Examples of the polymer having a hydrophilic group include a (meth)acrylic polymer having a hydrophilic group, a polyglycerin ester, and a polyalkylene glycol, and a (meth)acrylic polymer having a hydrophilic group is preferred.

[0230] The slipping agent is preferably one or more selected from the group consisting of silicone oil, paraffin oil, oils and fats, (meth)acrylic polymers having a hydrophilic group, polyglycerin esters, and polyalkylene glycols, more preferably one or more selected from silicone oil and (meth)acrylic polymers having a hydrophilic group, and even more preferably silicone oil. Furthermore, from the viewpoints of ease of preparation of composition A2 and the antifouling properties of the antifouling coating film A2 formed, it is preferable that the composition contains a (meth)acrylic polymer having a hydrophilic group, and it is more preferable that the composition contains both silicone oil and a (meth)acrylic polymer having a hydrophilic group.

[0231] Silicone oil The silicone oil has low interfacial tension and its properties are unlikely to change even in environments such as low temperatures, so it easily migrates to the surface of the antifouling coating film A2, effectively improving the ability to prevent adhesion of aquatic organisms (antifouling properties) and damage resistance. One type of silicone oil may be used, or two or more types may be used.

[0232] The viscosity of the silicone oil at 25°C is preferably 10 mPa·s or more, more preferably 20 mPa·s or more, even more preferably 40 mPa·s or more, still more preferably 60 mPa·s or more, and particularly preferably 80 mPa·s or more, from the standpoints of improving the coatability of the resulting composition A2, imparting lubricity to aquatic organisms to the formed antifouling coating film A2, and improving the antifouling properties, and is preferably 10,000 mPa·s or less, more preferably 5,000 mPa·s or less, and even more preferably 4,000 mPa·s or less. The viscosity of silicone oil at 25°C is measured using a B-type rotational viscometer.

[0233] The kinematic viscosity of the silicone oil at 25°C is preferably 10 mm, in order to improve the applicability of the resulting composition A2, to provide the antifouling coating film A2 formed with slipperiness against aquatic organisms, and to improve the antifouling properties. 2 / s or more, preferably 30 mm 2 / s or more, more preferably 50 mm 2 / s or more, preferably 5,000 mm 2 / s or less, preferably 4,000 mm 2 / s or less, and more preferably 3,500 mm 2 / s or less. The kinematic viscosity of the silicone oil at 25°C is a value measured in accordance with JIS Z 8803:2011.

[0234] When composition A2 contains silicone oil, the solid content thereof is preferably 1% by mass or more, more preferably 3% by mass or more, and even more preferably 5% by mass or more, relative to 100% by mass of the solid content of composition A2, from the viewpoint of easily forming an antifouling coating film A2 that has excellent formability and antifouling properties, and is preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less.

[0235] Examples of silicone oils include dimethyl silicone (polydimethylsiloxane, unmodified silicone) and modified silicone. The silicone oil is preferably a silicone oil having no reactive groups, such as those described in the section on curable polyorganosiloxanes.

[0236] As the dimethyl silicone, a commercially available product may be used. An example of the commercially available product is "KF-96-100cs" (manufactured by Shin-Etsu Chemical Co., Ltd., kinematic viscosity (25°C): 100 mm 2 / s), "KF-96-1,000cs" (Shin-Etsu Chemical Co., Ltd., kinematic viscosity (25°C): 1,000 mm 2 / s) etc.

[0237] Examples of the modified silicone include compounds in which some methyl groups in dimethyl silicone are substituted with organic groups other than methyl groups, and specific examples include phenyl-modified silicone, polyether-modified silicone, long-chain alkyl-modified silicone, higher fatty acid ester-modified silicone, fluorinated alkyl-modified silicone, carbinol-modified silicone, carboxy-modified silicone, amino-modified silicone, epoxy-modified silicone, (meth)acrylic-modified silicone, mercapto-modified silicone, and phenol-modified silicone.

[0238] The structure of the modified silicone may be a side chain modified type, a both end modified type, a one end modified type, a block type, a side chain and one end modified type, or a side chain and both end modified type.

[0239] Among the modified silicones, one or more selected from phenyl-modified silicones and polyether-modified silicones are preferred, since they can impart an appropriate thixotropy to composition A2, improve its coatability, and easily form an antifouling coating film A2 with excellent antifouling properties.

[0240] The phenyl modification rate of the phenyl-modified silicone is preferably 3 to 50%, more preferably 3 to 20%, and even more preferably 4 to 10%, from the viewpoint of easily forming an antifouling coating film A2 that is excellent in formability and antifouling properties. The phenyl modification rate is the number of phenyl groups relative to the total number of phenyl groups and methyl groups bonded to silicon, expressed as a percentage.

[0241] The kinematic viscosity of the phenyl-modified silicone at 25°C is preferably 10 to 5,000 mm from the viewpoints of the coating workability of the resulting composition A2 and the antifouling properties of the antifouling coating film A2 formed. 2 / s, more preferably 50 to 4,000 mm 2 / s, more preferably 80 to 3,500 mm 2 / s or less.

[0242] A commercially available product may be used as the phenyl-modified silicone. An example of the commercially available product is "KF-50-100cs" (manufactured by Shin-Etsu Chemical Co., Ltd., phenyl modification rate = 5%, kinematic viscosity (25°C): 100 mm 2 / s), "KF-50-1,000cs" (Shin-Etsu Chemical Co., Ltd., phenyl modification rate = 5%, kinematic viscosity (25 °C): 1,000 mm 2 / s), "KF-50-3,000cs" (Shin-Etsu Chemical Co., Ltd., phenyl modification rate = 5%, kinematic viscosity (25 °C): 3,000 mm 2 / s) etc.

[0243] When composition A2 contains a phenyl-modified silicone, the solids content thereof is preferably 0.1% by mass or more, more preferably 1% by mass or more, even more preferably 3% by mass or more, and particularly preferably 5% by mass or more, relative to 100% by mass of the solids content of composition A2, from the viewpoint of enabling the easy formation of an antifouling coating film A2 that has excellent formability and antifouling properties, and is preferably 30% by mass or less, more preferably 25% by mass or less, and even more preferably 20% by mass or less.

[0244] Examples of the structure of the polyether-modified silicone include a side chain-modified type, a both-end-modified type, a one-end-modified type, a block type, a side chain and one-end-modified type, and a side chain and both-end-modified type, with the side chain-modified type and both-end-modified type being preferred, and the both-end-modified type being more preferred.

[0245] Examples of the polyether (polyalkylene glycol) constituting the polyether group (polyalkylene glycol group) of the polyether-modified silicone include polyethylene glycol, polypropylene glycol, and a copolymer of ethylene glycol and propylene glycol, with a copolymer of polyethylene glycol and polypropylene glycol being preferred.

[0246] The proportion of polyether moieties in the polyether-modified silicone structure is preferably 10 to 60 mass %, more preferably 15 to 50 mass %, and even more preferably 20 to 50 mass %, because polyether-modified silicone can easily form an antifouling coating film A2 that has excellent formability and antifouling properties.

[0247] In the polyether-modified silicone, when the polyether group has an ethyleneoxy (EO) group and a propyleneoxy (PO) group, the molar ratio of the ethyleneoxy (EO) group to the propyleneoxy (PO) group in the polyether group [EO / PO] is preferably 0.5 or more, and is preferably 9.0 or less, more preferably 5.0 or less, even more preferably 4.0 or less, and particularly preferably 3.5 or less, from the viewpoint of being able to easily form an antifouling coating film A2 that has excellent long-term antifouling properties, etc.

[0248] The molar ratio of EO groups to PO groups in the polyether-modified silicone is, for example, 1 It can be measured by H-NMR measurement. in particular, 1 It can be calculated from the following formula based on the integral values ​​of the methyl groups of the PO groups at about 0.8 to 1.2 ppm and the non-methyl groups of the EO groups and PO groups at about 3 to 4 ppm in H-NMR. EO / PO = {([Integral value of approximately 3-4 ppm] - [Integral value of approximately 0.8-1.2 ppm]) / 4} / {[Integral value of approximately 0.8-1.2 ppm] / 3}

[0249] When composition A2 contains a polyether-modified silicone containing an ethyleneoxy partial structure (-OC2H4-), the total content of the ethyleneoxy partial structures is preferably 0.1 to 10 parts by mass, more preferably 0.3 to 5 parts by mass, per 100 parts by mass of the dimethylsiloxane partial structure (-Si(CH3)2-O-) of the silicone, in order to impart good antifouling properties to the antifouling coating film A2 that is formed.

[0250] The kinematic viscosity of the polyether-modified silicone at 25°C is preferably 10 to 5,000 mm from the viewpoints of the coating workability of the resulting composition A2 and the antifouling properties of the antifouling coating film A2 formed. 2 / s, more preferably 50 to 2,000 mm 2 / s, more preferably 100 to 500 mm 2 / s.

[0251] As the polyether-modified silicone, a commercially available product may be used, and an example of the commercially available product is "X-22-4272" (manufactured by Shin-Etsu Chemical Co., Ltd., double-ended type, kinematic viscosity (25°C): 270 mm 2 / s), "KF-6020" (Shin-Etsu Chemical Co., Ltd., side chain type, kinematic viscosity (25°C): 180 mm 2 / s), "FZ-2203" (manufactured by Toray Dow Corning Co., Ltd., block type), etc.

[0252] When composition A2 contains a polyether-modified silicone, the solids content thereof is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, even more preferably 0.5% by mass or more, relative to 100% by mass of the solids content of composition A2, from the viewpoint of enabling the easy formation of an antifouling coating film A2 that has excellent formability and antifouling properties, and is preferably 20% by mass or less, more preferably 10% by mass or less, even more preferably 5% by mass or less.

[0253] Paraffin oil The paraffin oil is not particularly limited, but liquid paraffin is preferred. One type of paraffin oil may be used, or two or more types may be used.

[0254] The kinematic viscosity of the paraffin oil at 25°C is preferably 10 mm from the viewpoint of the coating workability of the resulting composition A2 and the antifouling properties of the antifouling coating film A2 formed. 2 / s or more, preferably 50 mm 2 / s or more, more preferably 100 mm 2 / s or more, preferably 5,000 mm 2 / s or less, preferably 2,000 mm 2 / s or less, more preferably 500 mm 2 / s or less.

[0255] When composition A2 contains paraffin oil, the solid content thereof is preferably 0.1 mass% or more, more preferably 0.3 mass% or more, relative to 100 mass% of the solid content of composition A2, in order to facilitate the formation of an antifouling coating film A2 that is excellent in formability and antifouling properties, and is preferably 20 mass% or less, more preferably 10 mass% or less.

[0256] ·Oils and fats Examples of the fats and oils include esters obtained from fatty acids and glycerin, and include animal fats and oils, vegetable fats and oils, etc. One type of oil or fat may be used, or two or more types may be used.

[0257] - (Meth)acrylic polymer with hydrophilic groups The (meth)acrylic polymer having a hydrophilic group preferably contains a structural unit derived from a monomer having a hydrophilic group, more preferably contains a structural unit derived from a monomer having a hydrophilic group and a structural unit derived from a hydrophobic monomer, and even more preferably consists of a structural unit derived from a monomer having a hydrophilic group and a structural unit derived from a hydrophobic monomer. However, it contains structural units derived from (meth)acrylic monomers. The (meth)acrylic polymer having a hydrophilic group may be used alone or in combination of two or more.

[0258] It is believed that the hydrophilic groups in the (meth)acrylic polymer cause the hydrophilic portions of the (meth)acrylic polymer in the formed antifouling coating film A2 to dissolve or swell and gradually migrate to the surface of the antifouling coating film A2, thereby efficiently inhibiting the adhesion of aquatic organisms. Furthermore, because of the (meth)acrylic structure, it undergoes gradual hydrolysis, changing its affinity with water, which is thought to enable the antifouling properties to be maintained for a long period of time.

[0259] The content of structural units derived from monomers having a hydrophilic group in the (meth)acrylic polymer having a hydrophilic group is preferably 1 to 100% by mass, more preferably 3 to 80% by mass, even more preferably 5 to 70% by mass, and particularly preferably 10 to 60% by mass.

[0260] As the hydrophilic group, from the viewpoint of antifouling properties, an ether group or a hydroxyl group is preferred, and an ether group is more preferred.

[0261] As the monomer having a hydrophilic group, from the viewpoint of antifouling properties, a monomer having a polyalkylene glycol group, a monomer having a hydroxyl group, and a monomer having an alkoxyalkyl group are preferred, and a monomer having a polyalkylene glycol group is more preferred.

[0262] Specific examples of monomers having a hydrophilic group are, from the viewpoint of further improving the antifouling properties of the antifouling coating film A2 to be formed, preferably one or more selected from polyalkylene glycol (meth)acrylate, hydroxyalkyl (meth)acrylate, alkoxyalkyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, 4-(meth)acryloylmorpholine, and vinylpyrrolidone, more preferably one or more selected from polyalkylene glycol (meth)acrylate and hydroxyalkyl (meth)acrylate, and even more preferably polyalkylene glycol (meth)acrylate.

[0263] Examples of polyalkylene glycol (meth)acrylates include compounds in which one end of a polyalkylene glycol is bonded to (meth)acrylic acid directly via an ester bond or a linking group, and the remaining end is a hydroxyl group or an alkoxy group, and compounds in which the remaining end is an alkoxy group are preferred. Among these, compounds in which one end of a polyalkylene glycol is directly ester-bonded to (meth)acrylic acid are preferred, and compounds in which the remaining end is an alkoxy group are more preferred.

[0264] The terminal (meth)acrylic acid is preferably acrylic acid or methacrylic acid, more preferably acrylic acid. Examples of the terminal alkoxy group include a methoxy group, a phenoxy group, and an octoxy group, with a methoxy group and a phenoxy group being preferred, and a methoxy group being more preferred.

[0265] The polyalkylene glycol constituting the polyalkylene glycol (meth)acrylate is preferably polyethylene glycol, polypropylene glycol, or a copolymer of ethylene glycol and propylene glycol, and more preferably polyethylene glycol.

[0266] The average number of alkylene glycol units constituting the polyalkylene glycol in the polyalkylene glycol (meth)acrylate is preferably 2-25, more preferably 3-15, and even more preferably 5-12.

[0267] Specific examples of the polyalkylene glycol (meth)acrylate include 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 (meth)acrylate, octoxypoly(ethylene glycol-propylene glycol) mono(meth)acrylate, dodecyloxypolyethylene glycol mono(meth)acrylate, octadecyloxypolyethylene glycol mono(meth)acrylate, and nonylphenoxypolypropylene glycol acrylate, with methoxypolyethylene glycol mono(meth)acrylate being preferred.

[0268] As the polyalkylene glycol (meth)acrylate, commercially available products may be used, and examples of such commercially available products include 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 M-230G (methoxypolyethylene glycol #1000 methacrylate); Kyoeisha Chemical Co., Ltd.'s 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 041MA (methoxypolyethylene glycol methacrylate); NOF Corporation's Blemmer ANP-300 (nonylphenoxy polypropylene glycol acrylate), Blemmer AP-400 (polypropylene glycol monoacrylate), Blemmer 70PEP-350B (polyethylene glycol polypropylene glycol monomethacrylate), Blemmer 55PET-800 (polyethylene glycol tetramethylene glycol monomethacrylate), Blemmer 50POEP-800B (octoxypolyethylene glycol polypropylene glycol methacrylate); Osaka Organic Chemical Industry Co., Ltd.'s Viscoat #MTG (methoxypolyethylene glycol acrylate), and the like.

[0269] Examples of the hydroxyalkyl (meth)acrylate include hydroxyethyl (meth)acrylate and hydroxypropyl (meth)acrylate. As the hydroxyalkyl (meth)acrylate, commercially available products may be used, and examples of such commercially available products include Light Ester HOA(N) (2-hydroxyethyl acrylate), Light Ester HO-250(N) (2-hydroxyethyl methacrylate), and Light Ester HOP(N) (2-hydroxypropyl methacrylate), manufactured by Kyoeisha Chemical Co., Ltd.

[0270] Examples of the alkoxyalkyl(meth)acrylate include methoxyethyl(meth)acrylate.

[0271] Examples of the tetrahydrofurfuryl (meth)acrylate include tetrahydrofurfuryl acrylate and tetrahydrofurfuryl methacrylate, with tetrahydrofurfuryl acrylate being more preferred.

[0272] The 4-(meth)acryloylmorpholine is preferably 4-acryloylmorpholine or 4-methacryloylmorpholine, and more preferably 4-acryloylmorpholine.

[0273] Examples of the vinylpyrrolidone include 1-vinyl-2-pyrrolidone (N-vinyl-2-pyrrolidone), 3-acetyl-1-vinylpyrrolidin-2-one, and 3-benzoyl-1-vinylpyrrolidin-2-one, with 1-vinyl-2-pyrrolidone being preferred.

[0274] The content of structural units derived from hydrophobic monomers in the (meth)acrylic polymer having a hydrophilic group is preferably 99% by mass or less, more preferably 97% by mass or less, even more preferably 95% by mass or less, particularly preferably 90% by mass or less, and is preferably 20% by mass or more, more preferably 30% by mass or more, and even more preferably 40% by mass or more.

[0275] The inclusion of structural units derived from hydrophobic monomers gives the film a high affinity with other components of the antifouling coating film A2, such as crosslinked silicones, and is thought to enable the film to exhibit a uniform slip effect on the surface of the antifouling coating film A2.

[0276] Examples of the hydrophobic monomer include alkyl(meth)acrylates having a branched, linear, or cyclic alkyl group having 1 to 30 carbon atoms, aryl(meth)acrylates having an aromatic group having 6 to 10 carbon atoms, and (meth)acrylic group-containing silicones. Of these, alkyl(meth)acrylates and (meth)acrylic group-containing silicones are preferred, and alkyl(meth)acrylates are more preferred.

[0277] The alkyl group of the alkyl (meth)acrylate preferably has 4 to 18 carbon atoms, more preferably 4 to 8 carbon atoms, and particularly preferably 4 to 6 carbon atoms. The alkyl group is preferably branched or linear, more preferably branched.

[0278] Specific examples of the alkyl (meth)acrylate 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, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 3,5,5-trimethylhexyl (meth)acrylate, lauryl (meth)acrylate, cetyl (meth)acrylate, stearyl (meth)acrylate, and isostearyl (meth)acrylate. Of these, n-butyl (meth)acrylate, isobutyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate are preferred.

[0279] The aromatic group of the aryl(meth)acrylate preferably has 6 to 7 carbon atoms. Specific examples of the aryl(meth)acrylate include phenyl(meth)acrylate and benzyl(meth)acrylate.

[0280] The (meth)acrylic group-containing silicone is preferably a methacrylic group-containing silicone. The (meth)acrylic group-containing silicone is preferably a compound in which a (meth)acrylic group is bonded to one end of a silicone main chain via a linking group, or a compound in which a (meth)acrylic group is bonded directly to one end of a silicone main chain, and more preferably a compound in which a (meth)acrylic group is bonded to one end of a silicone main chain via a linking group. The linking group is preferably a trimethylene group. Furthermore, it is more preferable that an alkyl group having 1 to 6 carbon atoms is present at the end opposite to the (meth)acrylic group, and it is more preferable that a butyl group is present.

[0281] The silicone main chain is preferably made of linear or branched dimethyl silicone (polydimethylsiloxane), and more preferably made of linear dimethyl silicone.

[0282] As the (meth)acrylic group-containing silicone, commercially available products may be used, and examples of such commercially available products include Silaplane TM-0701T (tris(trimethylsiloxy)silylpropyl methacrylate), Silaplane FM-0711 (methacrylic group-containing dimethylpolysiloxane, number average molecular weight 1,000), and Silaplane FM-0721 (methacrylic group-containing dimethylpolysiloxane, number average molecular weight 5,000), all manufactured by JNC Corporation.

[0283] The weight-average molecular weight (Mw) of the (meth)acrylic polymer having a hydrophilic group is preferably 1,000 or more, more preferably 3,000 or more, even more preferably 5,000 or more, and particularly preferably 7,000 or more, from the viewpoints of the viscosity of the obtained composition A2 and the antifouling properties of the antifouling coating film A2 to be formed, and is preferably 150,000 or less, more preferably 100,000 or less, even more preferably 50,000 or less, and particularly preferably 30,000 or less.

[0284] When composition A2 contains a (meth)acrylic polymer having a hydrophilic group, the solid content thereof is preferably 0.2% by mass or more, more preferably 0.8% by mass or more, even more preferably 2% by mass or more, particularly preferably 4% by mass or more, relative to 100% by mass of the solid content of composition A2, from the viewpoint of being able to easily form an antifouling coating film A2 that is excellent in formability and antifouling properties, and is preferably 30% by mass or less, more preferably 20% by mass or less, and even more preferably 10% by mass or less.

[0285] Polyglycerin ester The polyglycerol ester is preferably a polyglycerol fatty acid ester. One type of polyglycerol ester may be used, or two or more types may be used.

[0286] Polyglycerol fatty acid esters are, for example, esters obtained using polyglycerol and fatty acids. The fatty acids are preferably saturated or unsaturated fatty acids having 8 to 24 carbon atoms, and specific examples include caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, behenic acid, oleic acid, linoleic acid, and linolenic acid. The average number of repeating units of glycerin in the polyglycerin ester is preferably 3 to 100, more preferably 5 to 30. The polyglycerol ester may be a monoester having one ester group, a diester having two ester groups, or a polyester having three or more ester groups. Examples of polyglycerol fatty acid esters include the S Face series manufactured by Sakamoto Pharmaceutical Co., Ltd.

[0287] Polyalkylene glycol Examples of the polyalkylene glycol include polyethylene glycol, polypropylene glycol, copolymers of ethylene glycol and propylene glycol, and alkyl ethers of these. One type of polyalkylene glycol may be used, or two or more types may be used.

[0288] [Optional ingredients] Composition A2 may contain optional components other than the curable polyorganosiloxane and the slip agent. Examples of the optional components include at least one optional component selected from the group consisting of silica particles, pyrithione metal salts, oxidized polyethylene wax, coloring pigments, organic solvents, curing catalysts, organosilicon crosslinking agents, silane coupling agents, biological repellents other than pyrithione metal salts, pigments other than silica particles and coloring pigments, dehydrating agents other than organosilicon crosslinking agents, anti-sagging agents and anti-settling agents other than oxidized polyethylene wax, wetting and dispersing agents other than oxidized polyethylene wax, enzymes, flame retardants, and thermal conductivity improvers.

[0289] [Silica particles] It is preferable that composition A2 contains silica particles, since this can improve the fluidity and thixotropy of composition A2 and make it easy to form an antifouling coating film A2 that is excellent in hardness, flexibility, and strength. The silica particles may be used alone or in combination of two or more types.

[0290] As the silica particles, dry process silica and wet process silica are preferred, and dry process silica is more preferred.

[0291] The silica particles preferably contain at least one selected from the group consisting of hydrophobic silica particles and hydrophilic silica particles, and more preferably contain at least hydrophobic silica particles. The addition of hydrophobic silica particles is preferred from the viewpoints of improving the fluidity and thixotropy of the composition A2, and of improving the hardness, flexibility, and strength of the antifouling coating film A2 to be formed. Furthermore, it is preferable to add hydrophilic silica particles because they tend to reduce the viscosity of composition A2 and improve the antifouling properties of the antifouling coating film A2 that is formed.

[0292] The hydrophobic silica particles are hydrophobically treated silica (silica whose surface has been hydrophobized), and are obtained, for example, by treating the hydroxyl groups (silanol groups) bonded to silicon atoms on the silica surface with a hydrophobizing agent, and examples thereof include aqueous wet-process silica and hydrophobic fumed silica.

[0293] Examples of the hydrophobic treatment agent include organodisilazanes, organoalkoxysilanes, organochlorosilanes, cyclic organopolysilazanes, and organopolysiloxanes, and among these, organodisilazanes, organoalkoxysilanes, organochlorosilanes, and organopolysiloxanes are preferred. Specific examples of these include hexamethyldisilazane, hexaethyldisilazane, hexapropyldisilazane, 1,3-diethyl-1,1,3,3-tetramethyldisilazane, 1,3-dimethyl-1,1,3,3-tetraethyldisilazane, 1,3-divinyltetramethyldisilazane, 1,3-diallyltetramethyldisilazane, 1,3-dibutenyltetramethyldisilazane, 1,3-dipentenyltetramethyldisilazane, 1,3-dihexenyltetramethyldisilazane, 1,3-diheptenyltetramethyldisilazane, 1,3-dioctenyltetramethyldisilazane, 1,3-dinonenyltetramethyldisilazane, 1,3-didekenyltetramethyldisilazane, and 1,3-divinyltetramethyldisilazane. silazane compounds such as tetraethyldisilazane and 1,3-dimethyltetravinyldisilazane; alkoxysilane compounds such as methyltrimethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, vinyltrimethoxysilane, allyltrimethoxysilane, and butenyltrimethoxysilane; chlorosilane compounds such as methyltrichlorosilane, trimethylchlorosilane, triethylchlorosilane, tripropylchlorosilane, dimethyldichlorosilane, diethyldichlorosilane, dipropyldichlorosilane, dimethylvinylchlorosilane, and allyldimethylchlorosilane; and siloxane compounds such as hexamethylcyclotrisiloxane and octamethylcyclotetrasiloxane. From the standpoint of workability and reactivity with silanol groups on the silica surface, silazane compounds, chlorosilane compounds, and siloxane compounds are preferred, with hexamethyldisilazane, 1,3-divinyltetramethyldisilazane, methyltrichlorosilane, dimethyldichlorosilane, hexamethylcyclotrisiloxane, and octamethylcyclotetrasiloxane being more preferred, and hexamethyldisilazane, 1,3-divinyltetramethyldisilazane, and dimethyldichlorosilane being even more preferred.

[0294] As the hydrophobic silica particles, commercially available products may be used, and examples of such commercially available products include "AEROSIL R974" and "AEROSIL RX200" manufactured by Nippon Aerosil Co., Ltd.

[0295] Examples of hydrophilic silica particles include untreated silica (surface-untreated silica), and more specifically, dry process silica (fumed silica, anhydrous silica), wet process silica (hydrated silica), etc., with dry process silica being preferred and fumed silica being more preferred. As the hydrophilic silica particles, commercially available products may be used, and examples of such commercially available products include "AEROSIL 200" manufactured by Nippon Aerosil Co., Ltd.

[0296] When composition A2 contains silica particles, the content thereof is preferably 0.1% by mass or more, more preferably 1% by mass or more, and even more preferably 3% by mass or more, relative to 100% by mass of the solid content of composition A2, from the viewpoint of easily forming an antifouling coating film A2 having excellent strength and hardness, and is preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 10% by mass or less.

[0297] When composition A2 contains silica particles, the content thereof is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, and even more preferably 3 parts by mass or more, per 100 parts by mass of curable polyorganosiloxane, from the viewpoint of being able to easily form an antifouling coating film A2 having excellent strength and hardness, and is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and even more preferably 15 parts by mass or less.

[0298] <Pyrithione metal salt> Composition A2 may contain a metal salt of pyrithione for the purpose of enhancing the antifouling properties of the antifouling coating film A2 to be formed. Examples of metal pyrithione salts include copper pyrithione and zinc pyrithione, and among these, copper pyrithione is preferred because it can easily form an antifouling coating film A2 that has excellent antifouling properties. One type of pyrithione metal salt may be used, or two or more types may be used.

[0299] When composition A2 contains a pyrithione metal salt, the content thereof is preferably 0.5% by mass or more, more preferably 1.0% by mass or more, even more preferably 3.0% by mass or more, and particularly preferably 5.0% by mass or more, relative to 100% by mass of the solid content of composition A2, from the viewpoint of easily forming an antifouling coating film A2 having excellent antifouling properties, and is preferably 15% by mass or less, more preferably 13% by mass or less, and even more preferably 10% by mass or less, from the viewpoint of easily obtaining composition A2 having excellent ease of preparation, dispersibility, and storage stability.

[0300] <Oxidized polyethylene wax> Composition A2 may contain oxidized polyethylene wax, because composition A2 can be easily prepared, has excellent dispersibility, and can easily have excellent storage stability. The oxidized polyethylene wax may be used alone or in combination of two or more.

[0301] An example of the oxidized polyethylene wax is a resin obtained by oxidizing polyethylene and introducing polar groups. Such oxidized polyethylene wax may be obtained by synthesis using a conventionally known method, or may be a commercially available product, such as "Disparlon 4200-20" manufactured by Kusumoto Chemicals Co., Ltd. or "ASA-D-120" manufactured by Ito Oil Refining Co., Ltd.

[0302] The acid value of the oxidized polyethylene wax is preferably 10 mgKOH / g or more, more preferably 15 mgKOH / g or more, and is preferably 40 mgKOH / g or less, more preferably 35 mgKOH / g or less, from the viewpoints of being able to easily obtain a composition A2 that is easy to prepare, has excellent dispersibility, and further has excellent storage stability.

[0303] When composition A2 contains an oxidized polyethylene wax, the solid content thereof is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and is preferably 3.0% by mass or less, more preferably 2.2% by mass or less, even more preferably 1.5% by mass or less, and particularly preferably 1.0% by mass or less, relative to 100% by mass of the solid content of composition A2, from the viewpoint of being able to easily obtain composition A2 that is easy to prepare, excellent in dispersibility and storage stability.

[0304] Furthermore, when composition A2 contains a pyrithione metal salt and an oxidized polyethylene wax, the solid content of the oxidized polyethylene wax per 100 parts by mass of the pyrithione metal salt is, for the same reasons, preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, even more preferably 1.0 parts by mass or more, and preferably 50 parts by mass or less, more preferably 40 parts by mass or less, even more preferably 30 parts by mass or less.

[0305] <Coloring pigments> Composition A2 preferably contains a color pigment. When composition A2 contains a color pigment, the coating strength of the antifouling coating film A2 to be formed can be increased. One type of color pigment may be used, or two or more types may be used.

[0306] The color pigment is not particularly limited, and examples thereof include inorganic pigments such as iron oxide, titanium oxide, carbon black, zinc oxide, aluminum silicate, alumina white, and barium sulfate; and organic pigments such as naphthol red, phthalocyanine blue, phthalocyanine green, and diketopyrrolopyrrole red. Among these, from the viewpoints of ease of preparation, coating workability, and storage stability of composition A2, and the antifouling properties of the antifouling coating film A2 formed, it is preferable to contain at least an inorganic pigment, more preferably one or more selected from iron oxide, titanium oxide, carbon black, zinc oxide, aluminum silicate, alumina white, and barium sulfate, even more preferably one or more selected from iron oxide, titanium oxide, and carbon black, and particularly preferably one or more selected from iron oxide and titanium oxide.

[0307] Examples of the iron oxide include red iron oxide, yellow iron oxide, and black iron oxide. The titanium oxide may be of the rutile, anatase or brookite type, and from the standpoints of the stability of the composition A2 and the antifouling coating film A2, ease of availability, etc., it is preferable to use the rutile type.

[0308] When composition A2 contains an inorganic pigment as a coloring pigment, the content thereof is preferably 0.01 to 20 mass%, more preferably 1 to 15 mass%, and even more preferably 3 to 12 mass%, relative to 100 mass% of the solid content of composition A2, from the viewpoints that composition A2 that is excellent in ease of preparation, coating workability, and storage stability can be easily obtained, and an antifouling coating film A2 that is excellent in antifouling properties can be easily formed.

[0309] On the other hand, when composition A2 contains an organic pigment, the content thereof is preferably 0.01 to 10 mass%, more preferably 0.1 to 9 mass%, and even more preferably 0.2 to 8 mass%, relative to 100 mass% of the solid content of composition A2, from the viewpoint of easily obtaining composition A2 that is easy to prepare, has excellent coating workability, and has excellent storage stability.

[0310] <Organic solvent> Composition A2 may contain an organic solvent, from the viewpoint of keeping the viscosity of composition A2 low and improving the coating workability. The organic solvent may be used alone or in combination of two or more.

[0311] Examples of organic solvents include aromatic hydrocarbon organic solvents, aliphatic hydrocarbon organic solvents, alicyclic hydrocarbon organic solvents, ketone organic solvents, alcohol organic solvents, and ester organic solvents. Aromatic hydrocarbon organic solvents and ketone organic solvents are preferred, and aromatic hydrocarbon organic solvents are more preferred.

[0312] Examples of the aromatic hydrocarbon organic solvent include toluene, xylene, and mesitylene, with xylene being preferred. Examples of the aliphatic hydrocarbon organic solvent include pentane, hexane, heptane, and octane. Examples of the alicyclic hydrocarbon organic solvent include cyclohexane, methylcyclohexane, and ethylcyclohexane. Examples of the ketone organic solvent include acetylacetone, acetone, methyl ethyl ketone, methyl isobutyl ketone, and dimethyl carbonate, with acetylacetone being preferred. Examples of the alcohol-based organic solvent include ethanol, n-propanol, isopropyl alcohol, n-butanol, and isobutanol. Examples of the ester-based organic solvent include ethyl acetate, propyl acetate, butyl acetate, and propylene glycol monomethyl ether acetate.

[0313] When composition A2 contains an organic solvent, the content thereof is preferably 3% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more, relative to 100% by mass of composition A2, from the viewpoint that composition A2 having excellent coating workability can be easily obtained, and is preferably 45% by mass or less, more preferably 40% by mass or less, and even more preferably 35% by mass or less, from the viewpoint that sagging of composition A2 during coating can be suppressed and the environmental load can be reduced.

[0314] <Curing catalyst> Composition A2 preferably contains a curing catalyst, as this can improve the curing rate and the film strength of the antifouling coating film. One type of curing catalyst may be used, or two or more types may be used.

[0315] As the curing catalyst, tin compounds, titanium compounds, organometallic compounds other than tin compounds and titanium compounds, metal salts of fatty acids, and amine compounds are preferred, and tin compounds, alkali metal salts of fatty acids, and amine compounds are more preferred. Furthermore, from the viewpoint of improving the curing rate under low-temperature and high-humidity environments, it is preferred to use metal salts of fatty acids and amine compounds, and it is more preferred to use alkali metal salts of fatty acids and amine compounds.

[0316] Examples of the tin compound include 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), dioctyltin bis(ethyl maleate), tin naphthenate, and tin oleate. Dibutyltin diacetate, dibutyltin acetoacetonate, dibutyltin dilaurate, dibutyltin diolate, dibutyltin oxide, dibutyltin dimethoxide, dibutyltin dipentanoate, dibutyltin dioctoate, and dibutyltin dineodecanoate are preferred, and dibutyltin dilaurate is more preferred.

[0317] As the tin compound, commercially available products may be used, and examples of such commercially available products include "NEOSTANN U-100" manufactured by Nitto Kasei Co., Ltd. and "Gleck TL" manufactured by DIC Corporation.

[0318] Examples of the titanium compound include tetraisopropoxytitanium, tetra-N-butoxytitanium, tetrakis(2-ethylhexoxy)titanium, dipropoxybis(acetylacetonato)titanium, and titanium isopropoxyoctyl glycol.

[0319] Examples of organometallic compounds other than the tin compounds and titanium compounds include zinc naphthenate, zinc stearate, zinc 2-ethyloctoate, iron 2-ethylhexoate, cobalt 2-ethylhexoate, manganese 2-ethylhexoate, cobalt naphthenate, and alkoxyaluminum compounds.

[0320] Examples of fatty acids that constitute the metal salts of fatty acids include acetic acid, 2-ethylhexanoic acid, octanoic acid, decanoic acid, neodecanoic acid, naphthenic acid, versatic acid, and oxalic acid.

[0321] Examples of metals that form metal salts include alkali metals such as lithium, sodium, and potassium, magnesium, calcium, neodymium, titanium, zirconium, iron, ruthenium, cobalt, nickel, copper, zinc, bismuth, and aluminum. Among these, alkali metals, and metals of Groups 10 to 12 such as nickel, copper, and zinc are preferred, with alkali metals and zinc being more preferred.

[0322] Examples of the amine compound include 1,6-hexanediamine-N,N,N,N-tetramethyl, 2,4,6-tris(dimethylaminomethyl)phenol, 1,2-dimethylimidazole, etc. Among these, 2,4,6-tris(dimethylaminomethyl)phenol is preferred.

[0323] When composition A2 contains a curing catalyst, the content thereof is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, even more preferably 0.3% by mass or more, relative to 100% by mass of the solid content of composition A2, from the viewpoint that composition A2 having an excellent curing rate can be easily obtained, and is preferably 10% by mass or less, more preferably 5% by mass or less, even more preferably 3% by mass or less.

[0324] When composition A2 contains a curing catalyst, the content thereof is preferably 0.03 to 30 parts by mass, more preferably 0.3 to 10 parts by mass, and even more preferably 0.5 to 5 parts by mass, per 100 parts by mass of the solid content of the curable polyorganosiloxane.

[0325] <Organosilicon Crosslinking Agent> Composition A2 preferably contains an organosilicon crosslinking agent, as this can improve the curing rate, the strength of the antifouling coating film A2 formed, and the adhesion to coating film S1 and tie coat T1. The organosilicon crosslinking agent is not limited to those intended for these functions, and may be added for the purpose of functioning as a wetting agent for color pigments, for example. The organosilicon crosslinking agent may be used alone or in combination of two or more.

[0326] The organosilicon crosslinking agent may be, for example, an organosilanes having three or four hydrolyzable groups bonded to a silicon atom, including partial condensates thereof. The organosilane having three hydrolyzable groups bonded to a silicon atom includes an organosilane having one more hydrocarbon group bonded to a silicon atom. The hydrolyzable group is preferably an alkoxy group, more preferably a methoxy group or an ethoxy group. The hydrocarbon group is preferably a hydrocarbon group having 1 to 6 carbon atoms, more preferably a methyl group, an ethyl group, or a propyl group, and even more preferably a methyl group or an ethyl group.

[0327] Examples of the organosilicon crosslinking agent include tetraethyl orthosilicate, partial hydrolysis condensates of tetraethyl orthosilicate, alkyltrialkoxysilanes, and oximesilanes, with tetraethyl orthosilicate and partial hydrolysis condensates of tetraethyl orthosilicate being preferred.

[0328] As the tetraethyl orthosilicate, commercially available products may be used, and examples of such commercially available products include "Ethyl Silicate 28" manufactured by Colcoat Co., Ltd. and "Ethyl Orthosilicate" manufactured by Tama Chemicals Co., Ltd. Commercially available products may be used as the partial hydrolysis condensate of tetraethyl orthosilicate, and examples of such commercially available products include "Silicate 40" manufactured by Tama Chemical Industries Co., Ltd. and "WACKER SILICATE TES 40 WN" manufactured by Wacker Asahi Kasei Silicones Co., Ltd. As the alkyltrialkoxysilane, commercially available products may be used, and examples of such commercially available products include "KBM-13" manufactured by Shin-Etsu Chemical Co., Ltd. Commercially available oxime silanes may be used, and examples of such commercially available products include "X-93-4096" (vinylmethyltris(methylisobutylketoxime)silane) manufactured by Shin-Etsu Chemical Co., Ltd., and "MTO(MOS)" (methyltris(methylethylketoxime)silane) and "VTO(VOS)" (vinyltris(methylethylketoxime)silane) manufactured by Toray Industries, Inc.

[0329] When composition A2 contains an organosilicon crosslinking agent, the content thereof is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, even more preferably 0.3% by mass or more, based on 100% by mass of the solid content of composition A2, and is preferably 15% by mass or less, more preferably 12% by mass or less, even more preferably 9% by mass or less. When composition A2 contains an organosilicon crosslinking agent, the content thereof is preferably 0.03 parts by mass or more, more preferably 0.1 parts by mass or more, and even more preferably 0.5 parts by mass or more, per 100 parts by mass of the solid content of the curable polyorganosiloxane, and is preferably 20 parts by mass or less, more preferably 15 parts by mass or less, and even more preferably 10 parts by mass or less.

[0330] <Silane coupling agent> Composition A2 may contain a silane coupling agent, which can improve the curing rate, the curability of the antifouling coating film A2 formed, and the adhesion to coating film S1 and tie coat T1. Composition A2 preferably contains an organosilicon crosslinking agent and / or a silane coupling agent for the purpose of improving the curability and strength of the antifouling coating film A2 to be formed, as well as its adhesion to the coating film S1 and tie coat T1. The silane coupling agent may be used alone or in combination of two or more.

[0331] Examples of silane coupling agents include organic alkoxysilanes having at least one alkoxy group and at least one organic reactive group.

[0332] The alkoxy group is preferably a methoxy group or an ethoxy group, and more preferably a methoxy group. One to three alkoxy groups are bonded to the silicon atom, preferably two or three, and more preferably three.

[0333] Examples of the organic reactive group include an amino group, a mercapto group, an epoxy group, an isocyanate group, a ureido group, a vinyl group, a (meth)acrylic group, and a styryl group. Of these, an amino group, a mercapto group, an epoxy group, an isocyanate group, and a ureido group are preferred, an amino group, a mercapto group, and an epoxy group are more preferred, and an amino group is even more preferred.

[0334] Specific preferred organic reactive groups containing an amino group include a 2-(aminoethyl)-3-aminopropyl group and a 3-aminopropyl group.

[0335] Examples of the silane coupling agent 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. Of these, 3-(2-aminoethylamino)propyltrimethoxysilane, 3-aminopropyltrimethoxysilane, and 3-aminopropyltriethoxysilane are preferred, and 3-(2-aminoethylamino)propyltrimethoxysilane is more preferred. As the silane coupling agent, a condensation product of the above-mentioned compound may be used.

[0336] When composition A2 contains a silane coupling agent, the solid content thereof is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, and preferably 3% by mass or less, more preferably 1% by mass or less, relative to 100% by mass of the solid content of composition A2.

[0337] When composition A2 contains a silane coupling agent, the solid content thereof is preferably 0.03 parts by mass or more, more preferably 0.1 parts by mass or more, and preferably 3 parts by mass or less, more preferably 1 part by mass or less, per 100 parts by mass of the curable polyorganosiloxane.

[0338] <Biological repellents other than pyrithione metal salts> Composition A2 preferably contains a biological repellent other than a pyrithione metal salt (hereinafter also simply referred to as "biological repellent") for the purpose of enhancing the antifouling properties of the antifouling coating film A2 to be formed. The biological repellent can inhibit aquatic organisms from attaching to the surface of the antifouling coating film A2, thereby improving the antifouling properties. One type of biological repellent may be used, or two or more types may be used.

[0339] The biological repellent is preferably one that has a repellent effect against aquatic organisms and has a certain dissolution rate in water, and is preferably one or more selected from 4-bromo-2-(4-chlorophenyl)-5-(trifluoromethyl)-1H-pyrrole-3-carbonitrile (also known as tralopyril) and 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one (also known as DCOIT).

[0340] When composition A2 contains a biological repellent, the solid content thereof is preferably 0.1% by mass or more, more preferably 1% by mass or more, and even more preferably 5% by mass or more, relative to 100% by mass of the solid content of composition A2, from the viewpoint that composition A2 having excellent coatability can be easily obtained and an antifouling coating film A2 having excellent strength and antifouling properties can be easily formed, and is preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 10% by mass or less, relative to 100% by mass of the solid content of composition A2.

[0341] <Pigments other than silica particles and color pigments> Examples of pigments other than the silica particles and color pigments include talc, mica, calcium carbonate, barium carbonate, potassium feldspar, kaolin, and short glass fibers. The silica particles and the pigments other than the color pigment may be used alone or in combination of two or more kinds.

[0342] <Dehydrating agents other than organosilicon crosslinking agents> Examples of dehydrating agents other than the organosilicon crosslinking agents include zeolite, porous alumina, orthoesters such as alkyl orthoformate esters, orthoboric acid, and isocyanate compounds. The dehydrating agents other than the organosilicon crosslinking agent may be used alone or in combination of two or more.

[0343] <Anti-sagging and anti-settling agents other than oxidized polyethylene wax> Examples of anti-sagging and anti-settling agents other than the oxidized polyethylene wax include organic clay waxes (stearate salts of Al, Ca, Zn, lecithin salts, alkyl sulfonates, etc.), organic waxes (polyethylene wax, amide wax, polyamide wax, hydrogenated castor oil wax, etc.), and mixtures of organic clay waxes and organic waxes. The anti-sagging agent and anti-settling agent other than the oxidized polyethylene wax may be used alone or in combination of two or more kinds.

[0344] <Wetting and dispersing agents other than oxidized polyethylene wax> Examples of wetting and dispersing agents other than the oxidized polyethylene wax include known organic or inorganic wetting and dispersing agents, such as wetting and dispersing agents having a silicone main chain. As the wetting and dispersing agent other than the oxidized polyethylene wax, commercially available products may be used, and examples of such commercially available products include "KP-578" and "KF-6106" manufactured by Shin-Etsu Chemical Co., Ltd. The wetting and dispersing agent other than the oxidized polyethylene wax may be used alone or in combination of two or more.

[0345] <enzyme> Examples of the enzyme include serine protease, cysteine ​​protease, metalloproteinase, cellulase, hemicellulase, pectinase, and glycosidase. One type of enzyme may be used, or two or more types may be used.

[0346] <Flame retardant> Examples of the flame retardant include antimony oxide and paraffin oxide. The flame retardant may be used alone or in combination of two or more kinds.

[0347] <Thermal conductivity improver> Examples of the thermal conductivity improver include boron nitride and aluminum oxide. The thermal conductivity improver may be used alone or in combination of two or more.

[0348] [Embodiments of Composition A2] Composition A2 may be a one-component antifouling coating composition in which the above-mentioned raw materials are combined into one composition, or a two-component or more antifouling coating composition in which the above-mentioned raw materials are combined into two or more components that are mixed before application. However, from the viewpoint of being able to suppress deterioration during storage, a two-component or more antifouling coating composition is preferred, and from the viewpoint of ease of application, a one-component antifouling coating composition is preferred. Examples of the two-component antifouling coating composition include two-component antifouling coating compositions and three-component or more antifouling coating compositions, and from the viewpoint of coating workability, two-component antifouling coating compositions are preferred, and from the viewpoint of suppressing deterioration during storage, three-component or more antifouling coating compositions are preferred.

[0349] When composition A2 contains at least one selected from a curing catalyst, an organosilicon crosslinking agent, and a silane coupling agent, and when composition A2 is a two-component or greater composition, it is preferable that the curable polyorganosiloxane and the at least one selected from the curing catalyst, the organosilicon crosslinking agent, and the silane coupling agent are contained in different agents. When composition A2 contains at least one selected from silica particles, pyrithione metal salts, oxidized polyethylene wax, colored pigments, and biological repellents, it is preferable that the silica particles, pyrithione metal salts, oxidized polyethylene wax, colored pigments, and biological repellents are contained in the same agent as the curable polyorganosiloxane.

[0350] [Method of producing composition A2] The composition A2 is preferably produced as follows. It is preferable to first include a step of kneading the curable polyorganosiloxane and the silica particles. Heating may be performed during or after kneading. By pre-kneading these components, the affinity between the two components is improved, and aggregation of the silica particles and an increase in the viscosity of the composition A2 can be suppressed. The heating temperature is preferably 100° C. or higher, more preferably 100 to 300° C., and even more preferably 140 to 200° C. The pressure during heating is preferably normal pressure or reduced pressure, and the treatment time is preferably 3 to 30 hours. When the optional components are added to the composition A2, the composition A2 can be produced by mixing the obtained kneaded product with the optional components.

[0351] <Silicone Tie Coat T1> It is preferable to provide a silicone-based tie coat T1 between the coating film S1 and the antifouling coating film A2, as this makes it easier to obtain a substrate with a multilayer coating film that has better adhesion between the coating film S1 and the antifouling coating film A2. The tie coat T1 is preferably a coating formed from a composition containing a curable polyorganosiloxane and a slip agent.

[0352] The film thickness of the tie coat T1 may be adjusted appropriately depending on the desired application, but is preferably 50 to 200 μm, more preferably 75 to 150 μm.

[0353] [Composition T1] Composition T1 preferably comprises a curable polyorganosiloxane and a slip agent. An example of composition T1 is a composition similar to composition A2. That is, composition A2 can be used to form tie coat T1 and antifouling coating film A2, and in some cases there may not be much difference in composition between tie coat T1 and antifouling coating film A2. However, in the substrate with this multilayer coating film, the coating film having antifouling properties formed on the outermost surface of the substrate (the outermost surface opposite the substrate) is called antifouling coating film A2, and the coating film provided between coating film S1 and antifouling coating film A2 is called tie coat T1. When a tie coat T1 and an antifouling coating film A2 are formed on a coating film S1, the composition T1 for forming the tie coat T1 and the composition A2 for forming the antifouling coating film A2 may be the same composition, but it is preferable that they be compositions that differ in the types and amounts of raw materials used.

[0354] <Method for manufacturing substrate with multilayer coating film> The substrate with this multilayer coating film, which comprises a substrate, an antifouling coating film A1, and a coating film S1 in this order, can be produced, for example, by a method comprising: step (I) of applying or impregnating a substrate with the antifouling paint composition A1 to obtain a coated or impregnated body; step (II) of drying (curing) the coated or impregnated body to form the antifouling coating film A1; and step (III) of applying the composition S1 onto the antifouling coating film A1 formed in step (II) (the side of the antifouling coating film A1 opposite the substrate) and drying (curing) the applied composition S1 to form the coating film S1. The substrate with this multilayer coating film, which comprises a substrate, an antifouling coating film A1, a coating film S1, and an antifouling coating film A2 in this order, can be produced, for example, by a method including step (IV) of applying composition A2 onto coating film S1 formed in step (III) (the side opposite to the substrate side of coating film S1) and drying (curing) the applied composition A2 to form antifouling coating film A2. The substrate with this multilayer coating film, which comprises a substrate, antifouling coating film A1, coating film S1, tie coat T1, and antifouling coating film A2 in this order, can be produced, for example, by a method including: step (V) of applying composition T1 onto coating film S1 formed in step (III) (the side opposite to the substrate side of coating film S1) and drying (curing) the applied composition T1 to form tie coat T1; and step (VI) of applying composition A2 onto tie coat T1 formed in step (V) (the side opposite to the substrate side of tie coat T1) and drying (curing) the applied composition A2 to form antifouling coating film A2.

[0355] The coating or impregnation is preferably carried out so that the thickness of the resulting coating or tie coat falls within the above-mentioned range. In this case, the coating or tie coat of the desired thickness may be formed by a single coating or impregnation, or by two or more coatings or impregnations.

[0356] Examples of the application method include methods using a coating means such as an air spray, an airless spray, a brush, or a roller. The drying (curing) may be performed in a manner appropriately selected depending on the composition used, and may be, for example, natural drying (at room temperature) or drying using a drying means such as a heater.

[0357] The antifouling coating film A1 may be an antifouling coating film R1 (old antifouling coating film) that has been worn or deteriorated due to exposure to water (oceans, rivers, lakes, marshes, etc.) for a certain period of time and that needs to be repaired or repainted, but it is preferably an antifouling coating film R1 (old antifouling coating film) in terms of better exerting the effects of the present invention. The substrate with the present multilayer coating film comprising such an antifouling coating film R1 can be produced, for example, by a method comprising step (i) of cleaning the antifouling coating film R1 of a substrate with the antifouling coating film R1, and step (ii) of forming a coating film S1 on the antifouling coating film R1 after step (i). Here, the antifouling coating film R1 is an antifouling coating film formed from a composition containing a silyl ester polymer having a structural unit derived from triisopropylsilyl methacrylate, and is preferably an antifouling coating film formed from the antifouling paint composition A1. The substrate with this multilayer coating film comprising the antifouling coating film R1 may include a step (iii) of forming an antifouling coating film A2 on the coating film S1 formed in the step (ii) (the side of the coating film S1 opposite to the substrate), and may also include a step (iv) of forming a tie coat T1 on the coating film S1 formed in the step (ii) (the side of the coating film S1 opposite to the substrate), and a step (v) of forming an antifouling coating film A2 on the tie coat T1 formed in the step (iv) opposite to the coating film S1. These steps (ii) to (v) correspond to the above steps (III) to (VI), respectively.

[0358] Step (i) is a step of removing foreign matter (e.g., various aquatic organisms, oil, and dust) adhering to the antifouling coating film R1, and is also a step of roughening the surface described below. Specifically, it is not particularly limited as long as it is a step other than roughening using a power tool, but an example of this step is a step of washing the antifouling coating film R1 with water. The water washing may be carried out at a pressure of about 5 to 10 MPa, and the time for the water washing is not particularly limited as long as it is possible to remove foreign matter adhering to the antifouling coating film R1, but is, for example, 1 to 10 seconds.

[0359] Conventionally, when forming an epoxy resin coating film on an old antifouling coating film, a step of roughening the surface of the old antifouling coating film using a power tool equipped with a nonwoven abrasive material or the like has been carried out between the steps (i) and (ii) in order to prevent adhesion between the coating films. On the other hand, according to the present invention, because a specific antifouling coating film R1 is used, a substrate with a multilayer coating film having excellent adhesion between the antifouling coating film R1 and the coating film S1 can be obtained without performing a step of roughening the surface of the antifouling coating film R1 with a power tool. Therefore, the effects of the present invention are better exhibited, and from the standpoints of economy and work efficiency, it is preferable not to include a step of roughening the surface of the antifouling coating film R1 after step (i), specifically, a step of roughening the surface of the antifouling coating film R1 after step (i) with a power tool, between steps (i) and (ii). [Example]

[0360] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these examples in any way.

[0361] <Production Example a1-1> Production of copolymer solution (a1-1) The following reaction was carried out under atmospheric pressure and nitrogen atmosphere. A reaction vessel equipped with a stirrer, reflux condenser, thermometer, nitrogen inlet tube, and dropping funnel was charged with 428.6 parts by weight of xylene and 100 parts by weight of triisopropylsilyl methacrylate (TIPSMA). The mixture was heated to 80°C while stirring with a stirrer. While maintaining the temperature of the mixture in the reaction vessel at 80±5°C, a mixture consisting of 500 parts by weight of TIPSMA, 250 parts by weight of 2-methoxyethyl methacrylate (MEMA), 100 parts by weight of methyl methacrylate (MMA), 500 parts by weight of butyl acrylate (BA), and 13 parts by weight of 2,2'-azobisisobutyronitrile (AIBN) was added dropwise to the reaction vessel over 2 hours using the dropping funnel. After the addition, the reaction mixture was stirred at 80°C for 1 hour and at 80-95°C for 1 hour and 30 minutes, respectively. Thereafter, 1 part by mass of AIBN was added to the reaction solution four times every 30 minutes while maintaining the temperature at 95°C, and the liquid temperature was raised to 105°C to complete the polymerization reaction. Next, 238 parts by mass of xylene was added to the reaction vessel, and the solution was stirred until it became homogeneous, thereby obtaining a copolymer solution (a1-1).

[0362] <Production Examples a1-2 and ca1-1 to ca1-2> Production of copolymer solution (a1-2), copolymer solution (ca1-1) and copolymer solution (ca1-2) Instead of the monomer mixture used in Production Example a1-1, monomers of the types and amounts (parts by mass) shown in Table 1 were used, and the reaction was carried out in the same manner as in Production Example a1-1, while appropriately adjusting the reaction temperature, dropping time, amount of initiator, etc., to obtain copolymer solution (a1-2), copolymer solution (ca1-1), and copolymer solution (ca1-2), respectively. In Table 1, "MAAc" is an abbreviation for methacrylic acid.

[0363] The obtained copolymer solutions (a1-1) to (a1-2) and copolymer solutions (ca1-1) to (ca1-2) were used to measure various physical properties as follows. The results are shown in Table 1.

[0364] <Method for measuring the content of solids (heating residue) in copolymer solution> Copolymer solutions (a1-1) to (a1-2) and copolymer solutions (ca1-1) to (ca1-2) were weighed out and placed in metal test dishes of known mass, and the solutions were spread on the bottom of the test dishes. They were then placed in a thermostatic bath maintained at 105°C and heated for 3 hours. The test dishes were then removed from the thermostatic bath and allowed to cool to room temperature. They were then weighed again to determine the mass of the heating residue in the metal test dishes. The solid content (mass%) in the copolymer solutions was calculated using the following formula: Solid content in copolymer solution (mass%) = mass of heating residue (g) × 100 / mass of weighed copolymer solution (g)

[0365] <Method for measuring viscosity of copolymer solution> The viscosities (unit: mPa·s) of the copolymer solutions (a1-1) to (a1-2) and the copolymer solutions (ca1-1) to (ca1-2) were measured using an E-type viscometer under the following conditions. Viscosity measurement conditions Device: TVE-25 Viscometer (manufactured by Toki Sangyo Co., Ltd.) Rotor used: Standard rotor (1°34' x R24) Measurement temperature: 25℃

[0366] <Method for measuring weight-average molecular weight (Mw) of copolymer> The weight average molecular weights (Mw) of the copolymers in the copolymer solutions (a1-1) to (a1-2) and the copolymer solutions (ca1-1) to (ca1-2) were measured using gel permeation chromatography (GPC) under the following conditions. GPC measurement conditions Device: "HLC-8320GPC" (Tosoh Corporation) Column: "TSKgel guard column SuperMP(HZ)-M + TSKgel SuperMultiporeHZ-M + TSKgel SuperMultiporeHZ-M" (manufactured by Tosoh Corporation) Eluent: tetrahydrofuran (THF) Flow rate: 0.35mL / min Detector: RI Column thermostat temperature: 40℃ Calibration curve: Standard polystyrene and styrene monomer Sample preparation method: Each copolymer solution was diluted with THF, and then filtered through a membrane filter to obtain a filtrate, which was used as a GPC measurement sample.

[0367] <Method for measuring the acid value of the solid content of the copolymer solution> Copolymer solutions (a1-1) to (a1-2) and copolymer solutions (ca1-1) to (ca1-2) were weighed into 2.0 g beakers. Next, 60 mL of the dilution solution shown below was weighed into the beakers to dilute each copolymer solution. Then, using the apparatus and titration solution shown below, potentiometric titration of each diluted copolymer solution was performed, and the maximum slope of the titration curve was defined as the endpoint. A blank measurement was carried out in the same manner except that no copolymer solution was used, and the acid value of the solid content of the copolymer solution was calculated according to the following formula.

[0368] Diluent: toluene:ethanol:ultrapure water = 100:95:5 (volume ratio) Equipment: "Automatic titrator CPM-1750" (Hiranuma Sangyo Co., Ltd.) Titration solution: Ethanol potassium hydroxide solution (Junsei Chemical Co., Ltd.) (s = 0.1 mol / L, f = 1.001, or s = 0.01 mol / L, f = 1.005)

[0369] Acid value of solids (mg KOH / g) = {(qr) × s × 56.11 × f} / (p × content of solids in copolymer solution / 100) f: Factor of potassium hydroxide solution p: Weight of the copolymer solution weighed into the beaker (unit: g) q: Titration volume up to the maximum slope point of the titration curve when using a copolymer solution (unit: mL) r: Titration volume up to the maximum slope point of the titration curve in the blank measurement (unit: mL) s: Molar concentration of titrant (unit: mol / L)

[0370] <Production of Metal Ester Group-Containing Monomer> A reaction vessel equipped with a stirrer, a condenser, a thermometer, a dropping device, a nitrogen inlet tube, and a heating / cooling jacket was charged with 85.4 parts by mass of propylene glycol monomethyl ether and 40.7 parts by mass of zinc oxide, and the temperature was raised to 75°C with stirring. Subsequently, a mixture of 43.1 parts by mass of methacrylic acid, 36.1 parts by mass of acrylic acid, and 5.0 parts by mass of water was added dropwise at a constant rate over 3 hours from a dropping device. After the addition was completed, the mixture was stirred for another 2 hours, and then 36.0 parts by mass of propylene glycol monomethyl ether was added to obtain a reaction solution containing a metal ester group-containing monomer.

[0371] <Production Example ca1-3> Production of copolymer solution (ca1-3) A reaction vessel equipped with a stirrer, a condenser, a thermometer, a dropping device, a nitrogen inlet tube, and a heating / cooling jacket was charged with 15.0 parts by mass of propylene glycol monomethyl ether, 57.0 parts by mass of xylene, and 4.0 parts by mass of ethyl acrylate (EA), and the temperature was raised to 100±5°C with stirring. While maintaining the same temperature, 52.0 parts by mass of the reaction liquid containing the metal ester group-containing monomer obtained above (amount of metal ester group-containing monomer used: 23.4 parts by mass), 1.0 part by mass of MMA, 66.2 parts by mass of EA, 5.4 parts by mass of 2-methoxyethyl acrylate (MEA), 2.5 parts by mass of polymerization initiator 2,2'-azobisisobutyronitrile, 7.0 parts by mass of polymerization initiator 2,2'-azobis(2-methylbutyronitrile), 1.0 part by mass of chain transfer agent "Nofumer MSD" (manufactured by NOF Corporation), and 10.0 parts by mass of xylene were added dropwise into the reaction vessel from a dropping device over a period of 6 hours. After the dropwise addition was completed, 0.5 parts by mass of the polymerization initiator tert-butyl peroctoate (TBPO) and 7.0 parts by mass of xylene were added dropwise over 30 minutes, and the mixture was stirred for another 1 hour and 30 minutes. Then, 4.4 parts by mass of xylene was added to obtain a pale yellow, transparent copolymer solution (ca1-3) containing a hydrolyzable polymer (metal ester group-containing copolymer).

[0372] <Production Example CA1-4> Production of copolymer solution (CA1-4) A reaction vessel equipped with a stirrer, condenser, thermometer, dropping device, nitrogen inlet tube, and heating / cooling jacket was charged with 15.0 parts by mass of propylene glycol monomethyl ether, 60.0 parts by mass of xylene, and 4.0 parts by mass of EA, and the mixture was heated to 100±5°C with stirring. While maintaining the same temperature, 40.2 parts by mass of the reaction liquid containing the metal ester group-containing monomer obtained above (amount of metal ester group-containing monomer used: 18.1 parts by mass), 15.0 parts by mass of MMA, 48.0 parts by mass of EA, 15.0 parts by mass of BA, 2.5 parts by mass of polymerization initiator 2,2'-azobisisobutyronitrile, 6.5 parts by mass of polymerization initiator 2,2'-azobis(2-methylbutyronitrile), 1.2 parts by mass of chain transfer agent "Nofumer MSD", and 10.0 parts by mass of xylene were added dropwise from the dropping device into the reaction vessel over 6 hours. After the addition was completed, 0.5 parts by mass of the polymerization initiator tert-butyl peroctoate and 7.0 parts by mass of xylene were added dropwise over 30 minutes, and the mixture was stirred for another 1 hour and 30 minutes. After that, 8.0 parts by mass of xylene was added to obtain a pale yellow, transparent copolymer solution (ca1-4) containing a hydrolyzable polymer (metal ester group-containing copolymer).

[0373] The resulting copolymer solutions (ca1-3) and (ca1-4) were used to measure various physical properties as follows. The results are shown in Table 1.

[0374] <Method for measuring the content of solids (heating residue) in copolymer solution> The copolymer solutions (ca1-3) and (ca1-4) were each dried in a hot air dryer at 105°C for 3 hours to volatilize the solvent, and the heating residue was measured. The solid content (mass%) in the copolymer solution was calculated using the following formula. Solid content in copolymer solution (mass%) = heating residue (g) × 100 / mass of copolymer solution placed in hot air dryer (g)

[0375] <Method for measuring viscosity of copolymer solution> The viscosity of each of the copolymer solutions (ca1-3) and (ca1-4) at 25° C. was measured using an E-type viscometer (manufactured by Toki Sangyo Co., Ltd.).

[0376] <Method for measuring weight-average molecular weight (Mw) of copolymer> The Mw of the copolymer in the copolymer solutions (ca1-3) and (ca1-4) was measured using GPC under the following conditions. GPC measurement conditions Device: "HLC-8320GPC" (Tosoh Corporation) Column: Two "TSKgel SuperAWM-H" columns and one "TSKgel SuperAW2500" column connected together (both manufactured by Tosoh Corporation, inner diameter 6 mm, length 15 cm) Eluent: N,N-dimethylformamide (DMF) (20 mM lithium bromide added) Flow rate: 0.600ml / min Detector: RI Column thermostat temperature: 40℃ Standard material: polystyrene Sample preparation method: A small amount of calcium chloride was added to each copolymer solution, and the solution was dehydrated. After filtering through a membrane filter, the residue was used as the GPC measurement sample.

[0377] [Table 1]

[0378] <Production Example A1-1> Production of Antifouling Paint Composition A1-1 To a plastic container were added 8.5 parts by mass of xylene, 1.0 part by mass of Solvesso No. 100, 2.5 parts by mass of rosin, 0.5 parts by mass of ethyl silicate 28, and 21.0 parts by mass of the copolymer solution (a1-1) obtained in Production Example a1-1, and the mixture was mixed using a paint shaker until each component was uniformly dispersed or dissolved. Then, 4.0 parts by mass of talc, 4.0 parts by mass of zinc oxide, 50.0 parts by mass of cuprous oxide, 1.5 parts by mass of red iron oxide, 2.5 parts by mass of titanium oxide, 2.0 parts by mass of copper pyrithione, and 1.0 part by mass of anti-settling agent were added to the plastic container, and the mixture was stirred for 1 hour using a paint shaker to disperse these ingredients. After dispersion, 1.5 parts by mass of an anti-sagging agent was further added and stirred for 20 minutes using a paint shaker. The resulting mixture was then filtered through a filter net (opening: 80 mesh) to remove the residue and obtain a filtrate (antifouling coating composition A1-1).

[0379] <Production Examples A1-2 to A1-6 and Production Examples cA1-1 to cA1-5> Production of Antifouling Paint Compositions A1-2 to A1-6 and Antifouling Paint Compositions cA1-1 to cA1-5 Antifouling coating compositions were obtained in the same manner as in Production Example A1-1, except that the types and amounts (values, parts by mass) of the raw materials used were changed as shown in Table 2. Details of each raw material listed in Table 2 are shown in Table 3.

[0380] [Table 2]

[0381] [Table 3]

[0382] <Production Example S1-1> Production of epoxy resin coating composition S1-1 A 1000 mL plastic container was mixed with 20.0 parts by weight of epoxy resin 1, 2.5 parts by weight of vinyl chloride resin, 2.5 parts by weight of plasticizer, 21.0 parts by weight of talc, 11.0 parts by weight of barium sulfate, 7.0 parts by weight of aluminum paste, 1.5 parts by weight of titanium white, 0.2 parts by weight of carbon black, 1.0 parts by weight of anti-sagging agent 1, 11.3 parts by weight of xylene, 3.0 parts by weight of PGM, and 3.0 parts by weight of methyl isobutyl ketone. 200 parts by weight of glass beads were added and dispersed for 1 hour using a paint shaker. The resulting dispersion was filtered through a 60-mesh filter to prepare the main component (filtrate). In a 250 mL plastic container, 14.5 parts by mass of amine curing agent 1, 0.3 parts by mass of tertiary amine, 0.6 parts by mass of xylene, 0.5 parts by mass of n-butyl alcohol, and 0.1 parts by mass of silane coupling agent 2 were mixed and dispersed for 10 minutes using a paint shaker until uniform. The resulting dispersion was filtered through a 60-mesh filter to prepare the curing agent component (filtrate). The prepared main component and curing agent component were mixed to obtain an epoxy resin coating composition S1-1.

[0383] <Production Examples S1-2 to S1-9> Production of Epoxy Resin-Based Coating Compositions S1-2 to S1-9 The main component and curing agent component were prepared in the same manner as in Production Example S1-1, except that the types and amounts (values, parts by mass) of the raw materials used were changed as shown in Table 4, and an epoxy resin-based coating composition was obtained. Details of each raw material listed in Table 4 are shown in Table 5.

[0384] [Table 4]

[0385] [Table 5]

[0386] <Preparation of Mixtures of Curable Silicone and Silica Particles (Mixtures 1 to 5)> The curable silicone and silica particles shown in Table 6 were kneaded in the amounts shown in Table 6 to obtain a kneaded mixture. The viscosities in Table 6 are all values ​​at 25°C and were measured using a B-type rotational viscometer in accordance with JIS K 6249: 2003. The weight average molecular weights (Mw) in Table 6 were measured in the same manner as the weight average molecular weight (Mw) described below.

[0387] [Table 6]

[0388] <Synthesis of (meth)acrylic polymers having hydrophilic groups> The reaction was carried out under atmospheric pressure and a nitrogen atmosphere. A reaction vessel equipped with a stirrer, reflux condenser, thermometer, nitrogen inlet tube, and dropping funnel was charged with 42.86 parts by mass of methyl amyl ketone and heated with stirring until the methyl amyl ketone reached 100°C. While maintaining the temperature of the reaction mixture at 100±5°C, a mixture consisting of 40.0 parts by mass of NK Ester AM-90G (methoxypolyethylene glycol acrylate, average number of polyethylene glycol units: 9, manufactured by Shin-Nakamura Chemical Co., Ltd.), 60.0 parts by mass of isobutyl acrylate, and 4.0 parts by mass of 2,2'-azobis(2-methylbutyronitrile) was added dropwise to the reaction vessel over 4 hours. The mixture was then stirred for 2 hours while maintaining the temperature at 100±5°C, yielding a solution of a (meth)acrylic polymer having hydrophilic groups.

[0389] [Solid content] The resulting solution of the (meth)acrylic polymer having a hydrophilic group was dried at 105°C under 1 atmosphere for 3 hours, and the mass of the resulting solid content was divided by the mass of the solution before drying to determine the solid content (mass %), which was 70.3 mass %.

[0390] 〔viscosity〕 The viscosity (mPa·s) of the resulting solution of the (meth)acrylic polymer having hydrophilic groups was measured at a liquid temperature of 25°C using an E-type viscometer (TV-25, manufactured by Toki Sangyo Co., Ltd.) and found to be 109 mPa·s.

[0391] [Weight average molecular weight (Mw)] The Mw of the (meth)acrylic polymer having a hydrophilic group was measured by gel permeation chromatography (GPC) under the following conditions, and was found to be 9,100. ·GPC conditions Device: "HLC-8420GPC" (Tosoh Corporation) Column: TSKgel SuperH2000 and TSKgel SuperH4000 (Tosoh Corporation, 6 mm inner diameter, 15 cm length) connected together Eluent: tetrahydrofuran (THF) Flow rate: 0.600mL / min Detector: RI Column thermostat temperature: 40℃ Standard material: polystyrene Sample preparation method: THF was added to the obtained polymer solution and filtered through a membrane filter to obtain a sample for GPC measurement.

[0392] <Production Examples A2-1 to A2-3> Production of organopolysiloxane-based antifouling coating compositions A2-1 to A2-3 The raw materials listed in Table 7 were mixed and stirred according to the compounding amounts (values, parts by mass) listed in Table 7 to prepare three-component organopolysiloxane-based antifouling coating compositions (organopolysiloxane-based antifouling coating compositions A2-1 to A2-3) consisting of a main component, a curing agent component, and an additive component. Regarding the main component, the components other than the curable polyorganosiloxane 1 and kneaded material-1 listed in Table 7 were mixed and stirred with 10 parts by mass of xylene to prepare a mixture, and then the curable polyorganosiloxane 1, kneaded material-1 and the remaining xylene were stirred and mixed thereto to prepare the main component. When each of the compositions A2-1 to A2-3 was applied, the components (main agent component, curing agent component, and additive component) were thoroughly stirred and mixed using a disperser to make them uniform before use. Details of each raw material listed in Table 7 are shown in Table 9.

[0393] <Production Examples A2-4 to A2-7 and T1-1 to T1-3> Production of organopolysiloxane-based antifouling paint compositions A2-4 to A2-7 and silicone-based tie coat compositions T1-1 to T1-3 The raw materials listed in Table 8 were mixed and stirred according to the amounts (values, parts by mass) listed in Table 8 to prepare one-component organopolysiloxane-based antifouling coating compositions (organopolysiloxane-based antifouling coating compositions A2-4 to A2-7 and silicone-based tie coat compositions T1-1 to T1-3). The compositions shown in Table 8 were prepared by mixing and stirring each component except for the kneaded material and the slipping agent with 10 parts by mass of xylene to prepare a mixture, and then stirring and mixing the kneaded material, the slipping agent, and the remaining xylene into the mixture. Details of each raw material listed in Table 8 are shown in Table 9.

[0394] <Anti-sagging> Using a box-type sag tester described in JIS K 5400 (1990) 6.4, each composition was applied to a tin plate, the film thickness (wet film thickness) was measured with a wet film gauge, and then the tin plate was immediately stood vertically so that the track line of the sag tester was horizontal, and the sagging prevention property of the applied composition was measured. A test was deemed to have passed if the amount of composition that flowed into the space between the applied compositions was less than half of the space. The thickness of the applied film (wet film thickness) was gradually increased, and the limit of wet film thickness (μm) at which this pass was maintained was measured. The anti-sagging properties were tested using the compositions obtained in Production Examples A2-1 to A2-7 and T1-1 to T1-3 immediately after preparation and after storage at a temperature of 50°C for 30 days. The results are shown in Tables 7 and 8.

[0395] <Coating film appearance> The appearance of the coating film on each tin plate on which the anti-sagging property was measured was visually evaluated according to the following criteria. The results are shown in Tables 7 and 8.

[0396] Evaluation criteria 3: No agglomerates observed, and the coating surface is good 2: Aggregates are observed, but no abnormalities are observed on the coating surface (unevenness or wrinkles on the coating, etc.) 1: Aggregates are observed and abnormalities in the coating surface (unevenness or wrinkles in the coating, etc.) are observed

[0397] <Dynamic stain resistance> A sandblasted plate coated with an epoxy anticorrosion paint ("Banno 500" manufactured by Chugoku Toryo Co., Ltd.) was coated with an intermediate paint ("CMP Bioclean Tie Coat" manufactured by Chugoku Toryo Co., Ltd.) so that the thickness after drying (curing) would be 100 μm. After drying at room temperature for 24 hours, each of the compositions obtained in Production Examples A2-1 to A2-7 and T1-1 to T1-3 was painted at room temperature so that the thickness after drying (curing) would be 200 μm. This was then left at room temperature for one week to produce a test plate with an antifouling coating film.

[0398] A test plate with an antifouling coating film attached to the side of a rotating rotor was immersed in live sea waters off the coast of Kure, Hiroshima Prefecture, and rotated at a speed of approximately 15 knots. The test plate was positioned so that the antifouling coating surface was exposed to sufficient sunlight, creating conditions conducive to slime formation. Six and 12 months after immersion in the sea, the ratio of the area of ​​the area with slime to the total surface of the antifouling coating film on the test plate was visually observed and calculated, and evaluated according to the following criteria. The results are shown in Tables 7 and 8.

[0399] Evaluation criteria 5: No slime adhesion 4: Slime adhesion area is 20% or more but less than 40% of the entire antifouling coating surface 3: Slime adhesion area is 40% or more but less than 60% of the entire antifouling coating surface 2: Slime adhesion area is 60% or more but less than 80% of the entire antifouling coating surface 1: Slime adhesion area is 80% or more of the entire antifouling coating surface

[0400] [Table 7]

[0401] [Table 8]

[0402] [Table 9]

[0403] The kinematic viscosities in Table 9 are all values ​​at 25°C, measured in accordance with JIS Z 8803:2011.

[0404] [Examples 1 to 54 and Comparative Examples 1 to 45] An epoxy anticorrosion paint ("Banno 500" manufactured by Chugoku Toryo Co., Ltd.) was applied to a sandblasted steel plate (300 mm long x 100 mm wide x 2.3 mm thick) so that the dry coating film was 150 μm thick, and then the plate was dried at room temperature for one day to form an anticorrosion coating film. An epoxy binder paint ("Banno 500N" manufactured by Chugoku Paint Co., Ltd.) was applied on top of the formed anticorrosion coating film so that the dry film thickness was 100 μm, and the coating was dried at room temperature for one day to form a laminated primer coating film. Each antifouling coating composition listed in Table 2 was applied onto the formed laminated primer coating film to a dry film thickness of 100 μm, and dried at room temperature for 7 days to form antifouling coating film A1, thereby producing a test panel with antifouling coating film A1. The prepared test panels were immersed in the Seto Inland Sea for three months to prepare test panels with the old antifouling coating film A1.

[0405] The coating surface of the test panel with the old antifouling coating film A1 thus prepared was washed with water at a water pressure of 5 to 7 MPa for 5 to 7 seconds, and then dried for 1 day. Thereafter, each epoxy resin-based paint composition listed in Table 4 was applied to the old antifouling coating film A1 to a dry film thickness of 100 μm, and dried at room temperature for 1 week to form an epoxy resin-based coating film S1, thereby producing test panel 1 with epoxy resin-based coating film S1. Tables 10 and 11 show the symbols of the production examples (compositions) used to form the antifouling coating film A1 and the epoxy resin coating film S1 in each of the examples and comparative examples.

[0406] <Adhesion> The surface of the epoxy resin coating film S1 of the test panel 1 with the prepared epoxy resin coating film S1 was washed with water at a water pressure of 10 MPa from a location 10 cm away from the coating film surface for 3 to 5 seconds, and then the peeling state (adhesion) of the epoxy resin coating film S1 from the old antifouling coating film A1 was visually observed and evaluated according to the following evaluation criteria. The results are shown in Tables 10 and 11.

[0407] Evaluation criteria 5: No peeling observed 4: Peeling of 1 mm or less in length is observed 3: Peeling length is greater than 1 mm and less than 5 mm. 2: Peeling length is greater than 5 mm and less than 1 cm. 1: Peeling longer than 1 cm is observed

[0408] [Table 10]

[0409] [Table 11]

[0410] [Examples 55 to 198] In the same manner as in Example 1, a test panel with the old antifouling coating film A1 was prepared. The coating surface of the test panel with the old antifouling coating film A1 thus prepared was washed with water at a water pressure of 5 to 7 MPa for 5 to 7 seconds, and then dried for 1 day. Thereafter, each epoxy resin-based paint composition listed in Table 4 was applied to the old antifouling coating film A1 to a dry film thickness of 100 μm, and dried at room temperature for 1 day to form an epoxy resin-based coating film S1, thereby producing a test panel with the epoxy resin-based coating film S1. Each composition listed in Table 8 was applied to the epoxy resin coating film S1 of the test plate with the prepared epoxy resin coating film S1 so that the dry film thickness was 200 μm, and the plate was dried at room temperature for 1 day to form an antifouling coating film A2, thereby producing test plate 2 with the antifouling coating film A2. Tables 12 and 13 show the symbols of the production examples (compositions) used to form the antifouling coating film A1, the epoxy resin coating film S1, and the antifouling coating film A2 in each example.

[0411] <Delamination> A single incision was made in the surface of the antifouling coating film A2 of the test panel 2 with the antifouling coating film A2, reaching the epoxy resin coating film S1, using a single blade as specified in JIS J5600-5-6, and the surface was rubbed 20 times perpendicular to the incision with a paper cloth. The degree of delamination between the antifouling coating film A2 and the epoxy resin coating film S1 was visually observed and evaluated according to the following criteria. The results are shown in Tables 12 and 13. The observation of delamination was carried out on test panel 2 with antifouling coating film A2 on the day after its preparation (hereinafter referred to as "initial delamination"), and on test panel 2 with antifouling coating film A2 prepared and immersed in fresh water at 23°C for three months (hereinafter referred to as "accelerated delamination").

[0412] Evaluation criteria 5: No damage to the antifouling coating A2 other than the cuts. 4: Delamination occurred within 1 mm of the cut 3: Delamination occurred within 1mm to 3mm from the cut 2: Delamination occurred within 3mm to 10mm from the cut 1: Delamination occurred within 10 mm or more from the cut

[0413] [Table 12]

[0414] [Table 13]

[0415] [Examples 199 to 702] A test plate with an epoxy resin coating film S1 was prepared in the same manner as in Example 55. Silicone tie coat composition T1-2 or T1-3 listed in Table 8 was applied to the epoxy resin coating film S1 of the test plate with the prepared epoxy resin coating film S1 so that the dry film thickness was 100 μm, and the test plate was dried at room temperature for 1 day to form tie coat T1, thereby producing a test plate with tie coat T1. Each of the antifouling coating compositions listed in Table 7 or 8 was applied to the tie coat T1 of the test plate with the prepared tie coat T1 so that the dry film thickness was 200 μm, and the coating was dried at room temperature for 1 day to form an antifouling coating film A2, thereby producing a test plate 3 with the antifouling coating film A2. Tables 14 to 17 show the symbols of the production examples (compositions) used to form the antifouling coating film A1, the epoxy resin coating film S1, the tie coat T1, and the antifouling coating film A2 in each example.

[0416] <Delamination> A single incision was made in the surface of the antifouling coating film A2 of the prepared test panel 3 with the antifouling coating film A2, reaching the epoxy resin coating film S1, using a single blade as specified in JIS J5600-5-6, and the surface was rubbed 20 times perpendicular to the incision with a paper cloth. During this process, the degree of delamination between the epoxy resin coating film S1 and the test panel was visually observed and evaluated using the same evaluation criteria as for delamination in Example 55 and the like. The results are shown in Tables 14 to 17. The observation of delamination was carried out on test panel 3 with antifouling coating film A2 on the day after its preparation (hereinafter referred to as "initial delamination"), and on test panel 3 with antifouling coating film A2 prepared and immersed in fresh water at 23°C for three months (hereinafter referred to as "accelerated delamination").

[0417] [Table 14]

[0418] [Table 15]

[0419] [Table 16]

[0420] Table 17

Claims

1. base material, An antifouling coating film A1 containing a silyl ester polymer (a1) having a structural unit derived from trialkylsilyl methacrylate (a11), and Epoxy resin coating S1 A substrate with a multilayer coating film, comprising:

2. base material, an antifouling coating film A1 containing a silyl ester polymer (a1) having a structural unit derived from trialkylsilyl methacrylate (a11); Epoxy resin coating film S1, and Organopolysiloxane antifouling coating film A2 The multilayer coated substrate according to claim 1, comprising, in this order:

3. 3. The substrate with a multilayer coating film according to claim 2, further comprising a silicone-based tie coat T1 between the epoxy resin-based coating film S1 and the organopolysiloxane-based antifouling coating film A2.

4. The substrate with a multilayer coating film according to claim 1, wherein the antifouling coating film A1 further contains copper or a copper compound (a2).

5. 2. The substrate with a multilayer coating film according to claim 1, wherein the content of the silyl ester polymer (a1) in the antifouling coating film A1 is 5 to 50% by mass.

6. 2. The substrate with a multilayer coating film according to claim 1, wherein the content of structural units derived from trialkylsilyl methacrylate (a11) in the antifouling coating film A1 is 3 to 15 mass %.

7. 2. The substrate with a multilayer coating film according to claim 1, wherein the epoxy resin coating film S1 is a coating film formed from a composition S1 containing an epoxy resin, an amine-based curing agent, and a pigment.

8. The substrate with a multilayer coating film according to claim 2, wherein the organopolysiloxane-based antifouling coating film A2 is a coating film formed from a composition A2 containing a curable polyorganosiloxane and a slip agent.

9. 9. The substrate with a multilayer coating film according to claim 8, wherein the slipping agent is at least one selected from the group consisting of silicone oil, paraffin oil, oils and fats, (meth)acrylic polymers having a hydrophilic group, polyglycerin esters, and polyalkylene glycols.

10. A step (i) of cleaning the antifouling coating film R1 of a substrate having the antifouling coating film R1 to be repaired or repainted; and Step (ii) of forming an epoxy resin coating film S1 on the antifouling coating film R1 after step (i). Including, the antifouling coating film R1 is an antifouling coating film formed from a composition containing a silyl ester polymer having a structural unit derived from triisopropylsilyl methacrylate; A method for producing a substrate with a multilayer coating film.

11. 11. The method for producing a substrate with a multilayer coating film according to claim 10, further comprising a step (iii) of forming an organopolysiloxane-based antifouling coating film A2 on the side of the epoxy resin-based coating film S1 formed in the step (ii) opposite to the substrate.

12. A step (iv) of forming a silicone-based tie coat T1 on the side opposite to the substrate of the epoxy resin-based coating film S1 formed in the step (ii); and 11. The method for producing a substrate with a multilayer coating film according to claim 10, further comprising a step (v) of forming an organopolysiloxane-based antifouling coating film A2 on the side of the silicone-based tie coat T1 formed in the step (iv) opposite to the epoxy resin-based coating film S1.

13. The method for producing a substrate with a multilayer coating film according to any one of claims 10 to 12, which does not include a step of roughening the surface of the antifouling coating film R1 after step (i) between step (i) and step (ii).

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