JP7082659B2 - Antifouling paint composition, antifouling coating film, base material with antifouling coating film and antifouling method - Google Patents

Description

The present invention relates to an antifouling paint composition, an antifouling coating film formed using the same, a base material with an antifouling coating film, a method for producing the same, and an antifouling method.

Currently, as a method for preventing contamination by aquatic organisms such as ships, an antifouling paint containing a hydrolyzable polymer having a property of renewing the coating film from the surface in water is widely used.
An antifouling coating film using such a hydrolyzable polymer as a binder is hydrolyzed from the surface as the hydrolysis progresses in water, and the hydrolyzed portion is wiped off by a water stream to exhibit coating renewability. As a typical example thereof, a silyl ester-based polymer having a trialkylsilyl ester group as a hydrolyzable group is widely used. Antifouling coating compositions using such silyl ester-based polymers have been studied for a long time, and various further improvements in antifouling properties have been studied so far. For example, Patent Document 1 contains a polymer having a silyl ester group and a polymer having a structure in which a quaternary ammonium group and / or a quaternary phosphonium group neutralized by a conjugated base of a sulfonic acid is bonded to the main chain. Adhesion-suppressing coating compositions have been proposed.

Special Table 2017-535637

However, the antifouling coating composition using the silyl ester-based copolymer such as the antifouling coating composition disclosed in Patent Document 1 is in an environment affected by sunlight and gravity in water, for example, typically. There is a problem that stains by plants are likely to occur on the vertical portion of the bottom of the ship or the upper surface of the bilge keel provided between the vertical portion of the bottom and the flattening portion, and the antifouling property against moss is particularly poor.
In view of such problems, it is an object of the present invention to provide an antifouling coating composition capable of exhibiting antifouling performance even in the above environment. Furthermore, an object of the present invention is to provide an antifouling coating film formed from the antifouling coating composition, a substrate with an antifouling coating film, a method for producing the same, and an antifouling method.

As a result of diligent studies by the present inventors, they have found that the above problems can be solved by using the antifouling coating composition shown below, and have completed the present invention.
The gist of the present invention is as follows.

The present invention relates to the following [1] to [15].
[1] At least one sulfonic acid group-containing compound (B) selected from the group consisting of the silyl ester-based copolymer (A), the sulfonic acid compound, and the sulfonic acid-based polymer (however, the silyl ester-based compound is used together. An antifouling coating composition containing the polymer (A).
[2] The silyl ester-based copolymer (A) contains a structural unit derived from a silyl (meth) acrylate represented by the following formula (I), and the total structural unit of the silyl ester-based copolymer is 100% by mass. The antifouling coating composition according to [1], wherein the content of the structural unit derived from the silyl (meth) acrylate represented by the formula (I) is 40 parts by mass or more and 80 parts by mass or less.

（式（Ｉ）中、Ｒ^１は水素原子又はメチル基を示し、Ｒ^２、Ｒ^３及びＲ^４はそれぞれ独立に一価の炭化水素基を示す。）

(In formula (I), R ¹ represents a hydrogen atom or a methyl group, and R ² , R ³ and R ⁴ each independently represent a monovalent hydrocarbon group.)

[3] The antifouling coating composition according to [1] or [2], wherein the silyl ester-based copolymer (A) is a copolymer having a structural unit derived from triisopropylsilylmethacrylate.
[4] The antifouling coating composition according to any one of [1] to [3], wherein the sulfonic acid group-containing compound (B) is a compound represented by the following formula (VII).

（式（ＶＩＩ）中、Ｒ^３１は一価の炭化水素基を示し、ａは１以上５以下の整数を示す。）

(In the formula (VII), R ³¹ represents a monovalent hydrocarbon group, and a represents an integer of 1 or more and 5 or less.)

[5] The antifouling coating composition according to [4], wherein the sulfonic acid group-containing compound (B) is a monoalkylbenzene sulfonic acid in the formula (VII), where a is 1 and ^R31 is an alkyl group. ..
[6] The protection according to any one of [1] to [5], wherein the silyl ester-based copolymer (A) further has a structural unit derived from a compound represented by the following formula (V). Stain paint composition.

（式（Ｖ）中、Ｒ^２４は水素原子又はメチル基を示し、Ｒ^２５は一価の炭化水素基を示し、Ｒ^２６は二価の炭化水素基を示し、ｓは１以上３０以下の整数を示す。）

(In formula (V), R ²⁴ represents a hydrogen atom or a methyl group, R ²⁵ represents a monovalent hydrocarbon group, R ²⁶ represents a divalent hydrocarbon group, and s is an integer of 1 or more and 30 or less. Shows.)

[7] The content of the structural unit derived from the compound represented by the formula (V) with respect to 100 parts by mass of all the structural units of the silyl ester-based copolymer (A) is 5 parts by mass or more and 40 parts by mass or less. , [6] The antifouling coating composition.
[8] Any of [1] to [7], wherein the content of the silyl ester-based copolymer (A) in the solid content of the antifouling coating composition is 5% by mass or more and 50% by mass or less. The antifouling paint composition according to one.
[9] The antifouling coating composition according to any one of [1] to [8], wherein the silyl ester-based copolymer (A) has a weight average molecular weight of 3,000 or more and 70,000 or less.
[10] Any of [1] to [9], wherein the content of the sulfonic acid group-containing compound (B) in the solid content of the antifouling coating composition is 0.01% by mass or more and 7% by mass or less. The antifouling paint composition according to one.
[11] The antifouling coating composition according to any one of [1] to [10], further containing the imidazole compound (C).
[12] An antifouling coating film formed from the antifouling coating composition according to any one of [1] to [11].
[13] A substrate with an antifouling coating film coated with the antifouling coating film according to [12].
[14] The step (1-1) of applying or impregnating the base material with the antifouling coating composition according to any one of [1] to [11] to obtain a coated body or an impregnated body, and the coated body. Alternatively, a method for producing a base material with an antifouling coating film, which comprises a step (1-2) of drying the impregnated body.
[15] An antifouling method using the antifouling coating film according to [12].

According to the present invention, it is possible to provide an antifouling coating composition capable of exhibiting excellent antifouling performance against moss in an environment affected by sunlight and gravity in water. Further, according to the present invention, it is possible to provide an antifouling coating film formed from the antifouling coating composition, a substrate with an antifouling coating film, a method for producing the same, and an antifouling method.

Hereinafter, the antifouling paint composition, the antifouling coating film, the base material with the antifouling coating film, the method for producing the same, and the antifouling method according to the present invention will be described in detail.
In the following description, "(meth) acryloyl", "(meth) acrylic acid" and "(meth) acrylate" are "acryloyl or methacrylic acid", "acrylic acid or methacrylic acid", and "acrylate or methacrylate", respectively. Means.

[Anti-fouling paint composition]
The antifouling coating composition of the present invention (hereinafter, also simply referred to as “coating composition”) is selected from the group consisting of a silyl ester-based copolymer (A), a sulfonic acid compound, and a sulfonic acid-based polymer. It is characterized by containing at least one sulfonic acid group-containing compound (B).

According to the present invention, it is possible to provide an antifouling coating composition that exhibits excellent antifouling performance against moss in an environment affected by sunlight and gravity in water. Although the detailed mechanism of action for obtaining the above effects is not always clear, some of them are presumed as follows. That is, as the hydrolysis of the silyl ester group progresses in water, the antifouling coating film containing the silyl ester-based copolymer (A) forms a hydrophilic surface layer film called a hydrodissociation layer, but in water. On the surface affected by sunlight and gravity, the growth of moss tends to proceed easily in this hydrolyzed layer due to the efficiency of photosynthesis and the promotion of adhesion of seeds. However, when the coating film contains the sulfonic acid group-containing compound (B), it is considered that the coating film has excellent antifouling performance against moss because the thickness of the hydrolyzed dissociation layer tends to be kept thin.
Hereinafter, each component contained in the antifouling coating composition of the present invention will be described in detail.

<Cyril ester-based copolymer (A)>
The antifouling coating composition of the present invention contains a silyl ester-based copolymer (A).
In the present invention, the silyl ester-based copolymer (A) is a copolymer having a silyl ester group in its chemical structure, preferably (i) silyl (meth) acrylate (a1), and optionally (ii). It is a copolymer having a structural unit derived from the other monomer (a2). However, the silyl ester-based copolymer (A) is preferably a copolymer having substantially no structural unit derived from the sulfonic acid group-containing monomer (a3).
In the present invention, the "copolymer having a structural unit derived from A" means a copolymer in which the monomer compound A is introduced by a polymerization reaction or a chain transfer reaction. Therefore, when the monomeric compound A has a mercaptoalkyl group, the radical polymerization terminal abstracts the hydrogen atom of the mercaptoalkyl group (RSH), and the generated RS (sulfur radical) initiates polymerization. It is introduced into the silyl ester-based copolymer (A) in the form, and even in such a case, the silyl ester-based copolymer (A) has a structural unit derived from the monomer compound. ..
Hereinafter, each structural unit of the silyl ester-based copolymer (A) will be described.

[(I) Structural unit derived from silyl (meth) acrylate (a1)]
The silyl (meth) acrylate (a1) is a monomer represented by the following formula (I).

（式（Ｉ）中、Ｒ^１は水素原子又はメチル基を示し、Ｒ^２、Ｒ^３及びＲ^４はそれぞれ独立に一価の炭化水素基を示す。）

(In formula (I), R ¹ represents a hydrogen atom or a methyl group, and R ² , R ³ and R ⁴ each independently represent a monovalent hydrocarbon group.)

In the formula (I), R ¹ represents a hydrogen atom or a methyl group, and is preferably a methyl group from the viewpoint of improving the long-term antifouling property and water resistance of the antifouling coating film.
In formula (I), R ² , R ³ and R ⁴ each independently represent a monovalent hydrocarbon group, and such hydrocarbon groups include linear, branched or cyclic alkyl groups and Aryl groups and the like can be mentioned.
The number of carbon atoms of the alkyl group is preferably 1 or more and 12 or less, more preferably 1 or more and 8 or less, and further preferably 1 or more and 4 or less. The aryl group has preferably 6 or more and 14 or less carbon atoms, and more preferably 6 or more and 10 or less carbon atoms.
From the viewpoint of imparting appropriate hydrolyzability to the antifouling coating film to improve long-term antifouling property and water resistance, ^{R2 ,} R3 and ^R4 are independently methyl group and ethyl group, respectively. It is preferably selected from an isopropyl group, an n-propyl group, a sec-butyl group, an n-butyl group, and a phenyl group, and all of R ² , R ³ and R ⁴ are an isopropyl group, an n-propyl group and a sec-butyl group. It is more preferable that the group is a group or an n-butyl group, and it is further preferable that all of ^{R2 ,} R3 and ^R4 are isopropyl groups.

That is, as the silyl (meth) acrylate (a1), trialkylsilyl (meth) acrylate, alkyldiarylsilyl (meth) acrylate, and aryldialkylsilyl (meth) acrylate are preferable, and trialkylsilyl (meth) acrylate is more preferable. , Triisopropylsilyl (meth) acrylate is particularly preferable, and triisopropylsilylmethacrylate is most preferable from the viewpoint of improving the internal water resistance of the antifouling coating film to be formed.
Further, the silyl ester-based copolymer (A) may have a structural unit derived from two or more different silyl (meth) acrylates (a1).
The structural unit derived from silyl (meth) acrylate (a1) has the same structure as the structural unit derived from (meth) acrylic acid by hydrolysis. Therefore, in the silyl ester-based copolymer (A), a part of the structural unit derived from the silyl (meth) acrylate (a1) has the same structure as the structural unit derived from (meth) acrylic acid by hydrolysis. You may. Further, the structural unit generated by hydrolysis may react with other components such as a metal oxide contained in the antifouling coating composition to further form a metal ester.

The total amount of the structural units derived from the silyl (meth) acrylate (a1) with respect to 100 parts by mass of all the structural units of the silyl ester-based copolymer (A) is from the viewpoint of improving the water resistance of the antifouling coating film. From the viewpoint of forming a coating film having an appropriate hydrolysis rate in water, it is preferably 10 parts by mass or more and 90 parts by mass or less, more preferably 30 parts by mass or more and 80 parts by mass or less, and further preferably 40 parts by mass or more and 80 parts by mass or less. It is 40 parts by mass or more, more preferably 40 parts by mass or less, and particularly preferably 45 parts by mass or more and 65 parts by mass or less.
The ratio of the content (mass) of each constituent unit derived from each monomer or the like in the silyl ester-based copolymer (A) sufficiently suppresses the hydrolysis of the silyl ester-based copolymer (A). If this is the case, for example, immediately after the polymerization of the silyl ester-based copolymer (A), or if the storage period of the coating composition using the silyl ester-based copolymer (A) is short, the above-mentioned monomers used in the polymerization reaction ( It can be regarded as the same as the ratio of the charged amount (mass) of the reaction raw material).
Further, the content of each monomer can also be determined by analyzing the obtained silyl ester-based copolymer (A) or the silyl ester-based copolymer (A) isolated from the coating composition. good. Specifically, the silyl ester-based copolymer (A) or its decomposition product is subjected to mass analysis, IR (inductive spectroscopy), NMR, ICP-MS (inductively coupled plasma mass spectrometer), ICP-AES (induction). A method of analysis by inductively coupled plasma emission spectroscopic analysis) or the like is exemplified.

[(Ii) Constituent unit derived from other monomer (a2)]
In the present invention, the silyl ester-based copolymer (A) preferably has a structural unit derived from the other monomer (a2).
The other monomer (a2) is a monomer other than the silyl (meth) acrylate (a1), and is a monomer copolymerizable with the silyl (meth) acrylate (a1). The other monomer (a2) preferably does not contain the sulfonic acid group-containing monomer (a3) described later.

Examples of the other monomer (a2) include an organosiloxane-containing monomer (a21), an alkoxyalkyl (meth) acrylate or an aryloxyalkyl (meth) acrylate (a22), an alkyl (meth) acrylate or an aryl (meth) acrylate. (A23), hydroxyalkyl (meth) acrylate (a24), glycidyl (meth) acrylate (a25), unsaturated carboxylic acid (a26), metal ester group-containing unsaturated monomer (a27), and other vinyl compounds (a28). ) Etc. can be mentioned.
Among these, from the viewpoint that the antifouling coating film to be formed has good antifouling properties, the organosiloxane-containing monomer (a21) and / or alkoxyalkyl (meth) acrylate or aryloxyalkyl (meth) acrylate (a22) are used. It is preferable to have an alkyl (meth) acrylate or an aryl (meth) acrylate (a23) from the viewpoint of improving the strength of the coating film. It is preferable to have the unsaturated carboxylic acid (a26) from the viewpoint of improving the crack resistance of the antifouling coating film after being immersed in seawater.

(Organosiloxane-containing monomer (a21))
The organosiloxane-containing monomer (a21) has a structure represented by the following formula (II).

（式（ＩＩ）中、Ｒ^１１、Ｒ^１２、及びＲ^１３はそれぞれ独立に、一価の炭化水素基を示し、Ｘはそれぞれ独立に、（メタ）アクリロイルオキシアルキル基又はメルカプトアルキル基を示し、ｍ及びｎはそれぞれ独立に０以上であり、ｐ及びｑはそれぞれ独立に０又は１であり、ｎ＋ｐ＋ｑは１以上である。）

In formula (II), R ¹¹ , R ¹² , and R ¹³ each independently represent a monovalent hydrocarbon group, and X each independently represents a (meth) acryloyloxyalkyl group or a mercaptoalkyl group. m and n are independently 0 or more, p and q are independently 0 or 1, and n + p + q is 1 or more.)

In formula (II), R ¹¹ , R ¹² and R ¹³ each independently represent a monovalent hydrocarbon group, and examples thereof include groups similar to R ² , R ³ and R ⁴ , which are easy to polymerize. From the viewpoint, an alkyl group is preferable, an alkyl group having 1 or more and 6 or less carbon atoms is more preferable, an alkyl group having 1 or more and 4 or less carbon atoms is further preferable, and a methyl group, an ethyl group, a propyl group and a butyl group are particularly preferable.
In formula (II), X independently represents a (meth) acryloyloxyalkyl group or a mercaptoalkyl group, and a (meth) acryloyloxyalkyl group is preferable from the viewpoint of uniform polymerization progress, and the viscosity of the polymer to be formed is preferable. A mercaptoalkyl group is also preferable from the viewpoint of reducing the amount of water and facilitating handling.
The (meth) acryloyloxyalkyl group in X is represented by the following formula (III).

（式（ＩＩＩ）中、Ｒ^２１は水素原子又はメチル基を示し、Ｒ^２２はアルキレン基を示し、＊は当該（メタ）アクリロイルオキシアルキル基が結合するＳｉとの結合位置を示す。）

(In formula (III), R ²¹ indicates a hydrogen atom or a methyl group, R ²² indicates an alkylene group, and * indicates a bond position with Si to which the (meth) acryloyloxyalkyl group is bonded.)

R ²² represents an alkylene group, and the alkylene group may be linear or branched, and the carbon number of the alkylene group is preferably 1 or more and 12 or less, more preferably 2 or more and 6 from the viewpoint of reactivity. Hereinafter, it is more preferably 2 or more and 4 or less.

The mercaptoalkyl group in X is represented by the following formula (IV).

（式（ＩＶ）中、Ｒ^２３はアルキレン基を示し、＊は当該メルカプトアルキル基が結合するＳｉとの結合位置を示す。）

(In formula (IV), R ²³ indicates an alkylene group, and * indicates a bonding position with Si to which the mercaptoalkyl group is bonded.)

R ²³ represents an alkylene group, and the alkylene group may be linear or branched, and the carbon number of the alkylene group is preferably 1 or more and 12 or less, more preferably 2 or more and 6 from the viewpoint of reactivity. Hereinafter, it is more preferably 2 or more and 4 or less.

Examples of X in the formula (II) include 2- (meth) acryloyloxyethyl group, 3- (meth) acryloyloxypropyl group, 4- (meth) acryloyloxybutyl group, mercaptomethyl group, and 2-mercaptoethyl group. Examples thereof include 2-mercaptopropyl group, 3-mercaptopropyl group and 4-mercaptobutyl group.

In formula (II), m and n are independently 0 or more, p and q are independently 0 or 1, and n + p + q is 1 or more.
In addition, m and n mean the average addition mole number of (SiR 122 O) and ^{(SiXR 13} _O ⁾ respectively.
The m + n in the formula (II) is preferably 2 or more. That is, the compound represented by the formula (II) preferably has a polyorganosiloxane moiety.
In this specification, when two or more different repeating units are described in parallel between [], the repeating units are repeated in any form and order of random, alternating, or block, respectively. Indicates that it may be. That is, for example, in the formula- [Y ₃ -Z ₃ ]-(where Y and Z indicate repeating units), whether it is a random shape such as -YYZZYZZ- or an alternating shape such as -YZZYZZ-,- It may be in the form of a block such as YYYZZ- or -ZZZZYY-.

In one embodiment, the silyl ester-based copolymer (A) has a structural unit derived from the compound (a211) in formula (II) in which n is 0, p is 1 and q is 0. Is preferable.
The antifouling coating composition containing the silyl ester-based copolymer (A) having a structural unit derived from such a compound (a211) can form an antifouling coating film having particularly excellent antifouling properties. preferable.
In such a compound (a211), m is preferably 3 or more and 200 or less, and more preferably 5 or more and 70 or less, from the viewpoint of easiness of polymerization and the like.

As such a compound (a211), a commercially available compound can be used, for example, FM-0711 (one-ended methacryloyloxyalkyl-modified organopolysiloxane, number average molecular weight Mn = 1,000) manufactured by JNC Co., Ltd. FM-0721 (one-ended methacryloyloxyalkyl-modified organopolysiloxane, number average molecular weight Mn = 5,000), FM-0725 (one-ended methacryloyloxyalkyl-modified organopolysiloxane, number average molecular weight Mn = 10,000), Shin-Etsu Chemical X-22-174ASX (one-ended methacryloyloxyalkyl-modified organopolysiloxane, functional group equivalent 900 g / mol), KF-2012 (one-ended methacryloyloxyalkyl-modified organopolysiloxane, functional group equivalent 4,600 g) manufactured by Kogyo Co., Ltd. / Mol), X-22-2426 (one-ended methacryloyloxyalkyl-modified organopolysiloxane, functional group equivalent 12,000 g / mol).

Further, as one form, the silyl ester-based copolymer (A) may have a structural unit derived from the compound (a212) in which n is 0 and p and q are 1 in the formula (II). preferable.
An antifouling coating composition containing a silyl ester-based copolymer (A) having a structural unit derived from such a compound (a212) is preferable in that the topcoat adhesion of the formed coating film is good.
In such a compound (a212), m is preferably 3 or more and 200 or less, and more preferably 5 or more and 70 or less, from the viewpoint of easiness of polymerization and the like.

As such a compound (a212), a commercially available compound can be used, for example, FM-7711 (both-terminal methacryloyloxyalkyl-modified organopolysiloxane, number average molecular weight Mn = 1,000) manufactured by JNC Co., Ltd. FM-7721 (both-ended methacryloyloxyalkyl-modified organopolysiloxane, number average molecular weight Mn = 5,000), FM-7725 (both-ended methacryloyloxyalkyl-modified organopolysiloxane, number average molecular weight Mn = 10,000), Shin-Etsu Chemical Co., Ltd. X-22-164 (both-terminal methacryloyloxyalkyl-modified organopolysiloxane, functional group equivalent 190 g / mol), X-22-164AS (both-ended methacryloyloxyalkyl-modified organopolysiloxane, functional group equivalent 450 g) manufactured by Kogyo Co., Ltd. / Mol), X-22-164A (both-terminal methacryloyloxyalkyl-modified organopolysiloxane, functional group equivalent 860 g / mol), X-22-164B (both-ended methacryloyloxyalkyl-modified organopolysiloxane, functional group equivalent 1630 g / mol) ), X-22-164C (both-terminal methacryloyloxyalkyl-modified organopolysiloxane, functional group equivalent 2,370 g / mol), X-22-164E (both-ended methacryloyloxyalkyl-modified organopolysiloxane, functional group equivalent 3,900 g) / Mol), X-22-167B (both-terminal mercaptoalkyl-modified organopolysiloxane, functional group equivalent 1,670 g / mol).

Further, as one form, it is also preferable that the silyl ester-based copolymer (A) has a structural unit derived from the compound (a213) in which n is 1 or more in the formula (II).
It is preferable that the silyl ester-based copolymer (A) has a structural unit derived from such a compound (a213) in that the viscosity is low and the handling is easy.
In such a compound (a213), m is preferably 50 or more and 1,000 or less, and n is preferably 1 or more and 30 or less.

As such a compound (a213), a commercially available compound can be used, for example, KF-2001 (side chain mercaptoalkyl-modified organopolysiloxane, functional group equivalent 1,900 g / mol) manufactured by Shin-Etsu Chemical Industry Co., Ltd.). , KF-2004 (side chain mercaptoalkyl modified organopolysiloxane, functional group equivalent 30,000 g / mol).

When the silyl ester-based copolymer (A) has a structural unit derived from the organosiloxane-containing monomer (a21), the content of the structural unit determines the antifouling performance of the antifouling coating film under alternating dry and wet conditions. From the viewpoint of water resistance and substrate adhesion, preferably 0.5 parts by mass or more and 50 parts by mass or less, more preferably 1 part by mass or more, with respect to 100 parts by mass of all the constituent units of the silyl ester-based copolymer (A). It is 30 parts by mass or less, more preferably 1.5 parts by mass or more and 15 parts by mass or less.

(Alkoxyalkyl (meth) acrylate or allyloxyalkyl (meth) acrylate (a22))
The alkoxyalkyl (meth) acrylate or allyloxyalkyl (meth) acrylate (a22) (hereinafter, also simply referred to as “monomer (a22))) may include those represented by the following formula (V). preferable.

（式（Ｖ）中、Ｒ^２４は水素原子又はメチル基を示し、Ｒ^２５は一価の炭化水素基を示し、Ｒ^２６は二価の炭化水素基を示し、ｓは１以上３０以下の整数を示す。）

(In formula (V), R ²⁴ represents a hydrogen atom or a methyl group, R ²⁵ represents a monovalent hydrocarbon group, R ²⁶ represents a divalent hydrocarbon group, and s is an integer of 1 or more and 30 or less. Shows.)

In the formula (V), R ²⁴ represents a hydrogen atom or a methyl group, and a hydrogen atom is preferable from the viewpoint of ease of polymerization, and a methyl group is preferable from the viewpoint of water resistance of the formed coating film.
In the formula (V), R ²⁵ represents a monovalent hydrocarbon group, and examples thereof include an alkyl group and an aryl group.
The monovalent hydrocarbon group in ^R25 is preferably a linear or branched alkyl group having 1 or more and 6 or less carbon atoms from the viewpoint of the stability of the antifouling coating composition and the physical properties of the formed coating film. And an aryl group, more preferably a linear alkyl group having 1 or more and 6 or less carbon atoms, and further preferably an alkyl group having 1 or more and 4 or less carbon atoms (for example, a methyl group, an ethyl group, a propyl group, and a butyl group). Group, etc.), and particularly preferably a methyl group.
In formula (V), R ²⁶ represents a divalent hydrocarbon group, and examples thereof include an alkylene group. The alkylene group is preferably an alkylene group having 2 or more and 6 or less carbon atoms, more preferably an alkylene group having 2 or more and 4 or less carbon atoms, still more preferably an ethylene group or a propylene group, and particularly preferably an ethylene group.
In the formula (V), s represents an integer of 1 or more and 30 or less, preferably an integer of 1 or more and 15 or less, more preferably an integer of 1 or more and 6 or less, and further preferably 1. When s is in such a range, the coating film formed by the antifouling coating composition containing the silyl ester-based copolymer (A) is imparted with appropriate hydrophilicity, and the antifouling coating has excellent water resistance. It is preferable because a film can be obtained.

Examples of the monomer (a22) include 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 4-methoxybutyl (meth) acrylate, 3-methoxy-n-propyl (meth) acrylate, and 2-. Propoxyethyl (meth) acrylate, 2-butoxyethyl (meth) acrylate, isobutoxybutyl diglycol (meth) acrylate, 2-phenoxyethyl (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, ethoxypolyethylene glycol (meth) acrylate , Butoxypolyethylene glycol (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate and the like. Among these, 2-methoxyethyl (meth) acrylate is preferable, and 2-methoxyethyl methacrylate is more preferable.
The monomer (a22) may be used alone or in combination of two or more, and may contain both an alkoxyalkyl (meth) acrylate and an allyloxyalkyl (meth) acrylate. good.

When the silyl ester-based copolymer (A) has a structural unit derived from the monomer (a22), the content of the structural unit is determined from the viewpoint of antifouling performance, water resistance, and hardness of the antifouling coating film. , 5 parts by mass or more and 40 parts by mass or less, more preferably 10 parts by mass or more and 35 parts by mass or less, still more preferably 15 parts by mass with respect to 100 parts by mass of all the constituent units of the silyl ester-based copolymer (A). It is 30 parts by mass or less.

(Alkyl (meth) acrylate or aryl (meth) acrylate (a23))
The alkyl group in the alkyl (meth) acrylate or aryl (meth) acrylate (a23) (hereinafter, also simply referred to as “monomer (a23)”) may be linear, branched or cyclic. Examples thereof include an alkyl group having 1 or more and 18 or less carbon atoms, more preferably 1 or more and 8 or less carbon atoms, still more preferably 1 or more and 4 or less carbon atoms, and the aryl group preferably has 6 or more and 14 or less carbon atoms. More preferably, an aryl group having 6 or more and 10 or less carbon atoms can be mentioned.
Examples of the monomer (a23) include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, and tert. -Butyl (meth) acrylate, sec-butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl Examples include (meth) acrylate, 3,5,5-trimethylhexyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, phenyl (meth) acrylate, and benzyl (meth) acrylate. Be done. Among these, methyl methacrylate is preferable from the viewpoint of obtaining an antifouling coating film having excellent coating film strength and, by extension, excellent antifouling performance, and butyl acrylate is preferable from the viewpoint of excellent water resistance and crack resistance of the antifouling coating film. preferable. In the present invention, it is also preferable to use methyl methacrylate and butyl acrylate together as the monomer (a23).
The monomer (a23) may be used alone or in combination of two or more. Further, the monomer (a23) may contain both an alkyl (meth) acrylate and an aryl (meth) acrylate.

When the silyl ester-based copolymer (A) has a structural unit derived from the monomer (a23), the content of the structural unit is 100 parts by mass of all the structural units of the silyl ester-based copolymer (A). On the other hand, it is preferably 0.2 parts by mass or more and 40 parts by mass or less, more preferably 1 part by mass or more and 35 parts by mass or less, and further preferably 3 parts by mass or more and 30 parts by mass or less.
When the silyl ester-based copolymer (A) has a structural unit derived from methyl methacrylate, the content of the structural unit is preferably 100 parts by mass with respect to 100 parts by mass of all the structural units of the silyl ester-based copolymer (A). Is 0.5 parts by mass or more and 40 parts by mass or less, more preferably 1 part by mass or more and 35 parts by mass or less, and further preferably 3 parts by mass or more and 30 parts by mass or less.
When the silyl ester-based copolymer (A) has a structural unit derived from butyl acrylate, the content of the structural unit is preferably 100 parts by mass with respect to 100 parts by mass of all the structural units of the silyl ester-based copolymer (A). Is 0.2 parts by mass or more and 20 parts by mass or less, more preferably 1 part by mass or more and 15 parts by mass or less, and further preferably 3 parts by mass or more and 10 parts by mass or less.

(Hydroxyalkyl (meth) acrylate (a24))
Examples of the hydroxyalkyl (meth) acrylate (a24) (hereinafter, also simply referred to as “monomer (a24)”) include hydroxymethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, and 2-hydroxypropyl (hereinafter, simply referred to as “monomer (a24)”). Examples thereof include meth) acrylate, 4-hydroxybutyl (meth) acrylate, and 2-hydroxy-3-phenoxypropyl (meth) acrylate.
The monomer (a24) may be used alone or in combination of two or more.
When having a structural unit derived from the monomer (a24), the content of the monomer (a24) is preferably 0.5 with respect to 100 parts by mass of all the structural units of the silyl ester-based copolymer (A). It is 3 parts by mass or more and 30 parts by mass or less, more preferably 1 part by mass or more and 20 parts by mass or less, and further preferably 2 parts by mass or more and 15 parts by mass or less.

(Glysidyl (meth) acrylate (a25))
Examples of the glycidyl (meth) acrylate (a25) (hereinafter, also simply referred to as “monomer (a25)”) include at least one selected from glycidyl acrylate and glycidyl methacrylate.
When the silyl ester-based copolymer (A) has a structural unit derived from the monomer (a25), the content of the structural unit is 100 parts by mass of all the structural units of the silyl ester-based copolymer (A). It is preferably 0.5 parts by mass or more and 30 parts by mass or less, more preferably 1 part by mass or more and 20 parts by mass or less, and further preferably 2 parts by mass or more and 15 parts by mass or less.

(Unsaturated carboxylic acid (a26))
The unsaturated carboxylic acid (a26) (hereinafter, also simply referred to as “monomer (a26)”) is a monomer having a carboxy group in the molecule.
Examples of the monomer (a26) include (meth) acrylic acid, (meth) acryloyloxyalkyl succinic acid, (meth) acryloyloxyalkylphthalic acid, (meth) acryloyloxyalkylhexahydrophthalic acid, itaconic acid, and maleic acid. , Maleic anhydride, itaconic acid, crotonic acid, 6-acrylamide hexane acid and the like, and (meth) acrylic acid is preferable from the viewpoint of easy handling and availability of the compound and the viscosity of the polymer obtained by polymerization.
When the silyl ester-based copolymer (A) has a structural unit derived from the monomer (a26), a part thereof is combined with other components such as metal oxides in a process such as preparation of an antifouling coating composition. React,
It may form a metal ester group or a metal salt.
When the silyl ester-based copolymer (A) has a structural unit derived from the monomer (a26), the content of the structural unit is 100 parts by mass of all the structural units of the silyl ester-based copolymer (A). It is preferably 0.01 parts by mass or more and 20 parts by mass or less, and more preferably 0.1 parts by mass or more and 10 parts by mass or less.

(Metal ester group-containing unsaturated monomer (a27))
The metal ester group-containing unsaturated monomer (a27) (hereinafter, also simply referred to as “monomer (a27)”) is a single amount having a metal ester group produced by binding a metal and a carboxylic acid. Point to the body. The "polyvalent metal ester group" or "divalent metal ester group" described later refers to a group formed by binding a polyvalent metal or a divalent metal to a carboxylic acid.
As the metal ester group, a polyvalent metal ester group is preferable, and a divalent metal ester group represented by the following formula (VI) is more preferable.

（式（ＶＩ）中、Ｍは金属を示し、＊は結合位置を示す。）

(In the formula (VI), M indicates a metal and * indicates a bonding position.)

Examples of the metal constituting the metal ester group include magnesium, calcium, neodymium, titanium, zirconium, iron, ruthenium, cobalt, nickel, copper, zinc, and aluminum.
In the formula (VI), M is a divalent metal, and a divalent metal can be appropriately selected and used from the above-mentioned metals. Among these, M is preferably a Group 10-12 metal such as nickel, copper, and zinc, more preferably selected from the group consisting of copper and zinc, and even more preferably zinc.
Examples of the monomer (a27) include zinc di (meth) acrylic acid, copper di (meth) acrylic acid, zinc acrylic acid (methacrylic acid), copper acrylic acid (methacrylic acid), and di (3-acryloyloxypropionic acid). ) Zinc, di (3-acryloyloxypropionic acid) copper, (meth) acrylic acid (naphthenic acid) zinc, (meth) acrylic acid (naphthenic acid) copper and the like.
When the silyl ester-based copolymer (A) has a structural unit derived from the monomer (a27), the content of the structural unit is 100 parts by mass of all the structural units of the silyl ester-based copolymer (A). It is preferably 0.5 parts by mass or more and 30 parts by mass or less, more preferably 1 part by mass or more and 20 parts by mass or less, and further preferably 2 parts by mass or more and 15 parts by mass or less.

(Other vinyl compounds (a28))
Examples of the other vinyl compound (a28) include styrene, α-methylstyrene, vinyl acetate, vinyl benzoate, vinyltoluene, acrylonitrile, vinylpyridine, vinylpyrrolidone, vinyl chloride and the like.
The other vinyl compound (a28) may be used alone or in combination of two or more.

It is preferable that the silyl ester-based copolymer (A) of the present invention does not substantially contain a structural unit derived from the sulfonic acid group-containing monomer (a3). In the present specification, substantially not contained means that the content is 0.1% by mass or less.
The sulfonic acid-containing monomer (a3) is a monomer containing a sulfonic acid group, and is, for example, vinyl sulfonic acid, styrene sulfonic acid, 3- (methacryloyloxy) propanesulfonic acid, and 2- (meth) acrylamide. -2-Methylpropanesulfonic acid and the like can be mentioned.

When the silyl ester-based copolymer (A) has a structural unit derived from the other monomer (a2), the structural unit derived from the silyl (meth) acrylate (a1) and the other monomer (a2) The mass ratio [(a1) / (a2)] with the constituent unit derived from is preferably 10/90 or more and 90/10 or less, more preferably 40/60 or more and 80/20 or less, and further preferably 45/55 or more. It is 70/30 or less, particularly preferably 45/55 or more and 65/35 or less. The mass ratio [(a1) / (a2)] can be calculated from the charging ratio of each monomer when producing the copolymer.

The silyl ester-based copolymer (A) can be produced, for example, by the following procedure.
A solvent is charged in a reaction vessel equipped with a stirrer, a condenser, a thermometer, a dropping device, a nitrogen introduction tube and a heating / cooling jacket, and heating and stirring are performed under a nitrogen stream under a temperature condition of 80 ° C. or higher and 90 ° C. or lower. While maintaining the same temperature, the monomer (a1) and optionally the monomer (a2), and a mixed solution of a polymerization initiator, a chain transfer agent, a solvent and the like are dropped into the reaction vessel from the dropping device. Then, the silyl ester-based copolymer (A) can be obtained by carrying out the polymerization reaction.

The polymerization initiator that can be used for producing the silyl ester-based copolymer (A) is not particularly limited, and various radical polymerization initiators can be used. Specifically, benzoyl peroxide, hydrogen peroxide, cumene hydroperoxide, tert-butyl hydroperoxide, potassium persulfate, sodium persulfate, 2,2'-azobis (isobutyronitrile) [AIBN], 2,2. Azo-based compounds such as'-azobis (2-methylbutyronitrile) [AMBN], 2,2'-azobis (2,4-dimethylvaleronitrile) [ADVN], 4,4'-azobis-4-cyanovaleric acid, etc. Compounds, tert-butyl peroxide [TBPO] and the like can be mentioned. These polymerization initiators may be used alone or in combination of two or more. These radical polymerization initiators may be added into the reaction system only at the start of the reaction, or may be added into the reaction system both at the start of the reaction and during the reaction.
The amount of the polymerization initiator used in the production of the silyl ester-based copolymer (A) is preferably 0.1 part by mass or more and 20 parts by mass or less with respect to 100 parts by mass in total of each of the monomers (reaction raw materials). More preferably, it is 0.5 parts by mass or more and 5 parts by mass or less.

The chain transfer agent that can be used in the production of the silyl ester-based copolymer (A) is not particularly limited, and is, for example, α-methylstyrene dimer, thioglycolic acid, diterpene, turpinolene, γ-terpinen; tert-dodecyl. Mercaptans such as mercaptan and n-dodecyl mercaptan; halides such as carbon tetrachloride, methylene chloride, bromoform, and bromotrichloroethane; secondary alcohols such as isopropanol and glycerin; and the like. These chain transfer agents may be used alone or in combination of two or more.
When a chain transfer agent is used in the production of the silyl ester-based copolymer (A), the amount used is 0.1 part by mass or more and 5 parts by mass with respect to 100 parts by mass in total of each of the monomers (reaction raw materials). The following is preferable.

Examples of the solvent that can be used for producing the silyl ester-based copolymer (A) include aromatic hydrocarbon-based solvents such as toluene, xylene, and mesitylen; propanol, butanol, propylene glycol monomethyl ether, and dipropylene glycol monomethyl. Alcoholic solvents such as ether; ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone and methyl amyl ketone; ester solvents such as ethyl acetate and butyl acetate; water and the like can be mentioned.

The weight average molecular weight (Mw) of the silyl ester-based copolymer (A) is preferably 3,000 or more and 70,000 or less from the viewpoint of coating workability of the coating composition and strength of the antifouling coating film. It is more preferably 10,000 or more and 50,000 or less.
The weight average molecular weight (Mw) of the silyl ester-based copolymer (A) refers to the value of gel permeation chromatography (GPC) measured by the method described in Examples.
The polydispersity (Mw / Mn) of the silyl ester-based copolymer (A) is not particularly limited, but is preferably 20 or less, more preferably 10 or less, from the viewpoint of obtaining a uniform coating composition.

The content of the silyl ester-based copolymer (A) in the antifouling coating composition of the present invention is preferably 5% by mass or more and 50% by mass or less, more preferably 10% by mass or more and 35 in the solid content of the coating composition. It is mass% or less, more preferably 10% by mass or more and 20% by mass or less.
In the present invention, when the antifouling coating composition contains two or more kinds of the silyl ester-based copolymer (A), the above content is preferable as the total content of the silyl ester-based copolymer (A). It is a range, and the same applies to each component described later.

<Sulfonic acid group-containing compound (B)>
The antifouling coating composition of the present invention contains a sulfonic acid compound and at least one sulfonic acid group-containing compound (B) selected from the group consisting of a sulfonic acid-based polymer.
In the present invention, the sulfonic acid compound is a compound having one or more sulfonic acid groups in the molecule, and means a sulfonic acid group-containing compound other than the sulfonic acid-based polymer, and specifically, has a repeating unit in the molecule. It means a compound that does not, that is, a low molecular weight compound.
The sulfonic acid-based polymer is a polymer having one or more sulfonic acid groups in the molecule, and excludes the silyl ester-based copolymer (A).
In the sulfonic acid group-containing compound (B) in the present invention, a part or all of the sulfonic acid groups may form a salt.

When the antifouling coating composition of the present invention contains the sulfonic acid group-containing compound (B), it is possible to form an antifouling coating film having good moss resistance even on the surface affected by sunlight and gravity in water. .. Further, when the antifouling coating composition contains the imidazole compound (C) described later, it is possible to suppress the deterioration of the storage stability thereof and to make it good.

The sulfonic acid group-containing compound (B) may be a sulfonic acid compound or a sulfonic acid-based polymer, but the antifouling coating composition has a low viscosity and is excellent in coating workability and storage stability. From the viewpoint, it is preferably a sulfonic acid compound.

The sulfonic acid compound is not particularly limited as long as it is a compound having one or more sulfonic acid groups in the molecule, and for example, methanesulfonic acid, trifluoromethanesulfonic acid, ethanesulfonic acid, vinylsulfonic acid, 1-propanesulfonic acid and the like. Examples thereof include aromatic sulfonic acid compounds such as aliphatic sulfonic acid compounds, benzene sulfonic acid, alkyl benzene sulfonic acid, diphenyl sulfonic acid and naphthalene sulfonic acid. Among these, aromatic sulfonic acid compounds are preferable from the viewpoint of being able to form an antifouling coating film having excellent moss resistance on the surface affected by sunlight and gravity in water, and a compound represented by the following formula (VII). Is more preferable.

（式（ＶＩＩ）中、Ｒ^３１は一価の炭化水素基を示し、ａは１以上５以下の整数を示す。）

(In the formula (VII), R ³¹ represents a monovalent hydrocarbon group, and a represents an integer of 1 or more and 5 or less.)

In formula (VII), R ³¹ represents a monovalent hydrocarbon group. Examples of the monovalent hydrocarbon group include a linear, branched or cyclic alkyl group, an aryl group and the like, and a part or all of the hydrogen atom bonded to the carbon atom is nitrogen, oxygen, sulfur, etc. It may be substituted with a substituent containing a heteroatom such as halogen, or a heteroatom such as nitrogen, oxygen or sulfur may be interposed between the carbon-carbon bonds of the hydrocarbon group. The substituent containing the heteroatom and the heteroatom intervening between the carbon-carbon bonds may have one kind or two or more kinds.
In the formula (VII), a represents an integer of 1 or more and 5 or less, preferably an integer of 1 or more and 3 or less, and more preferably 1.
When a plurality of R ^31s exist, they may be the same or different from each other.
Among these, monoalkylbenzenesulfonic acid in which a in the formula (VII) is 1 and the monovalent hydrocarbon group in ^R31 is an alkyl group is preferable from the viewpoint of availability and the like.
From the viewpoint of forming an antifouling coating film having excellent storage stability when the imidazole compound (C) described later is used in combination, R ³¹ is preferably an alkyl group having 2 or more and 30 or less carbon atoms, and a linear alkyl group is preferable. More preferably, a linear alkyl group having 10 or more and 18 or less carbon atoms is further preferable.
Examples of the monoalkylbenzene sulfonic acid include p-toluenesulfonic acid, m-xylene-4-sulfonic acid, cumenesulfonic acid (4-isopropylbenzenesulfonic acid), p-decylbenzenesulfonic acid, and p-undecylbenzenesulfonic acid. Examples thereof include p-dodecylbenzenesulfonic acid, p-tridecylbenzenesulfonic acid, p-tetradecylbenzenesulfonic acid and the like.

Commercially available sulfonic acid compounds can be used, for example, "Taika Power B120" (branched chain monoalkylbenzene sulfonic acid, acid value 173 mgKOH / g) and "Taika Power L121" (straight chain mono) manufactured by Teika Co., Ltd. Alkylbenzene sulfonic acid, acid value 179 mgKOH / g), "Taikapower L124" (linear monoalkylbenzene sulfonic acid, acid value 181 mgKOH / g), "Neoperex GS" manufactured by Kao Co., Ltd. (the carbon number of the linear alkyl group is Examples thereof include a linear monoalkylbenzene sulfonic acid mixture having an acid value of 11 or more and 16 or less, and an acid value of 186 mgKOH / g).

The sulfonic acid-based polymer means a polymer containing a structural unit derived from a monomer having at least one sulfonic acid group in one molecule as a structural unit of the sulfonic acid-based polymer. Examples of the monomer having a sulfonic acid group include styrene sulfonic acid, isoprene sulfonic acid, vinyl sulfonic acid, allyl sulfonic acid, isoamylene sulfonic acid, 2- (meth) acrylamide-2-methylpropane sulfonic acid, and metallicyl. Examples thereof include sulfonic acid (2-methyl-2-propen-1-sulfonic acid) and salts thereof. The sulfonic acid-based polymer may contain a structural unit derived from a monomer other than the sulfonic acid group-containing monomer. Examples of the monomer other than the sulfonic acid group-containing monomer include the monomer (a22) and the monomer (a23).
Examples of the sulfonic acid-based polymer include polystyrene sulfonic acid.

As the sulfonic acid group-containing compound (B), a compound having an arbitrary acid value can be used without limitation, but from the viewpoint of ease of handling and the viscosity of the coating composition, the imidazole compound (C) described later is used in combination. In some cases, from the viewpoint of obtaining an antifouling coating composition having excellent storage stability, the acid value of the sulfonic acid group-containing compound (B) is preferably 100 mgKOH / g or more and 310 mgKOH / g or less, and the imidazole compound (described later). From the viewpoint of being able to form an antifouling coating film having excellent crack resistance when used in combination with C), it is more preferably 150 mgKOH / g or more and 200 mgKOH / g or less.

As the sulfonic acid compound, a compound having an arbitrary molecular weight can be used without limitation, but it is excellent in terms of ease of handling, viscosity of the coating composition, and storage stability when the imidazole compound (C) described later is used in combination. From the viewpoint, the molecular weight of the sulfonic acid compound is preferably 170 g / mol or more and 570 g / mol or less, and it is excellent that an antifouling coating film having excellent crack resistance can be formed when the imidazole compound (C) described later is used in combination. From the viewpoint, it is more preferably 280 g / mol or more and 380 g / mol or less.

The weight average molecular weight (Mw) of the sulfonic acid-based polymer is preferably 3,000 or more and 100,000 or less, preferably 10,000 or more and 70,000 or less, from the viewpoint of coating workability of the coating composition. Is more preferable.

The content of the sulfonic acid group-containing compound (B) in the antifouling coating composition of the present invention is determined in the solid content of the coating composition from the viewpoint of coating workability of the coating composition and water resistance of the antifouling coating film to be formed. , Preferably 0.01% by mass or more and 7% by mass or less, more preferably 0.03% by mass or more and 5% by mass or less, still more preferably 0.05% by mass or more and 3% by mass or less, and particularly preferably 0.1% by mass. It is 2% by mass or less.
The sulfonic acid group-containing compound (B) may be used alone or in combination of two or more.
The sulfonic acid group-containing compound (B) may be used after being partially or completely neutralized. The neutralization of the sulfonic acid-based polymer may be carried out as a monomer, or may be neutralized after the polymer is formed.
Examples of the base used for neutralization include alkali metal hydroxides such as potassium hydroxide and sodium hydroxide, and amine compounds such as ammonia, triethanolamine and trimethylamine. As the salt of the sulfonic acid group-containing compound (B), an alkali metal salt is preferable, and a sodium salt is more preferable.

<Arbitrary ingredient>
The antifouling coating composition of the present invention contains, if necessary, an imidazole compound (C), a monocarboxylic acid compound (D), another antifouling agent (E), another binder component (F), a pigment (G), and an organic solvent ( It may contain H), an anti-sagging agent / anti-settling agent (I), a dehydrating agent (J), and a plasticizer (K).

[Imidazole compound (C)]
The antifouling coating composition of the present invention has the purpose of imparting good antifouling properties to the antifouling coating film to be formed and for the purpose of appropriately adjusting the hydrolysis rate of the silyl ester-based copolymer (A) in water. , The imidazole compound (C) may be contained.
Examples of the imidazole compound (C) include 2-methylimidazole, 4-methylimidazole, 4,5-dimethyl-1H-imidazole, (+/-) -4- [1- (2,3-dimethylphenyl) ethyl]. -1H-imidazole (also known as medetomidine) and the like can be mentioned, and from the viewpoint of forming an antifouling coating film having good fujitsubo resistance (+/-)-4- [1- (2,3-dimethylphenyl) ethyl]. -1H-imidazole is preferred. The imidazole compound (C) may be used alone or in combination of two or more.

The (+/-)-4- [1- (2,3-dimethylphenyl) ethyl] -1H-imidazole is represented by the following formula (VIII).

The (+/-)-4- [1- (2,3-dimethylphenyl) ethyl] -1H-imidazole has optical isomers, but even if only one of the optical isomers is used, it is a mixture in any ratio. May be. Further, as a part or all of (+/-)-4- [1- (2,3-dimethylphenyl) ethyl] -1H-imidazole, an imidazolium salt with the sulfonic acid group-containing compound (B) or the like can be used. An adduct to a metal or the like may be used, or an adduct to a metal or the like or an imidazolium salt may be formed in the antifouling coating composition or the antifouling coating film of the present invention.

When the antifouling coating composition of the present invention contains the imidazole compound (C), the content thereof is preferably in the antifouling coating composition from the viewpoint of imparting good antifouling properties to the formed antifouling coating film. Is 0.01% by mass or more and 5% by mass or less, more preferably 0.04% by mass or more and 1% by mass or less, and preferably 0.01% by mass or more and 5% by mass or less in the solid content of the antifouling coating composition. , More preferably 0.03% by mass or more and 3% by mass or less, further preferably 0.05% by mass or more and 1% by mass or less, and particularly preferably 0.05% by mass or more and 0.5% by mass or less.

When the antifouling coating composition of the present invention contains the imidazole compound (C), the content thereof is such that the equivalent value EQ represented by the following formula is 0 with respect to the sulfonic acid group-containing compound (B). The content of 5 or more and 10 or less is preferable, and the content of 0.8 or more and 7 or less is more preferable.
EQ = { _WB ÷ (56110 ÷ AV)} ÷ ( _WC ÷ MW _C )
( _WB and AV indicate the content and molecular weight of the sulfonic acid group-containing compound (B), respectively, and acid value (mgKOH / g), _WC and MW _C indicate the content and molecular weight of the imidazole compound (C).)

[Monocarboxylic acid compound (D)]
The antifouling coating composition of the present invention may contain a monocarboxylic acid compound (D).
In the present invention, the monocarboxylic acid compound (D) promotes the renewability of the antifouling coating film containing it from the surface in water, and when the antifouling coating film contains an antifouling agent. Is intended to enhance the antifouling property of the antifouling coating film by promoting the release of the antifouling agent into water, and further has a function of imparting an appropriate water resistance to the antifouling coating film. Further, when the antifouling coating composition contains the imidazole compound (C), it also has a function of acting together with the sulfonic acid group-containing compound (B) to improve the storage stability of the antifouling coating composition.

The monocarboxylic acid compound (D) is, for example, a compound in which one carboxy group is substituted for a saturated or unsaturated aliphatic hydrocarbon having 10 or more and 40 or less carbon atoms, or a saturated or unsaturated compound having 3 or more and 40 carbon atoms or less. A compound in which one carboxy group is substituted in the alicyclic hydrocarbon of the above, or a compound in which one carboxy group is substituted in an aliphatic hydrocarbon or a modified product of the alicyclic hydrocarbon is preferable.
Among these, avietic acid, neo-avietic acid, dehydroavietic acid, palastolic acid, isopimaric acid, pimaric acid, trimethylisobutenylcyclohexenecarboxylic acid, versatic acid, stearic acid, naphthenic acid and the like are preferable.

Further, rosins containing abietic acid, palastolic acid, isopimaric acid and the like as main components are also preferable. Examples of rosins include rosins such as gum rosin, wood rosin and tall oil rosin, hydrogenated rosins, disproportionated rosins, rosin derivatives such as rosin metal salts, and pineapples.
Examples of the trimethylisobutenylcyclohexenecarboxylic acid include a reaction product of 2,6-dimethylocta-2,4,6-triene and methacrylic acid, which are 1,2,3-trimethyl-. 5- (2-Methylpropa-1-en-1-yl) cyclohexa-3-ene-1-carboxylic acid, and 1,4,5-trimethyl-2- (2-methylpropa-1-en-1-yl) The main component is cyclohexa-3-ene-1-carboxylic acid (85% by mass or more).
The monocarboxylic acid compound (D) may be used alone or in combination of two or more.

A part or all of the monocarboxylic acid compound (D) in the present invention may form a salt. Examples of the salt of the monocarboxylic acid compound (D) include a zinc salt and a copper salt, and even if the salt is formed in advance before the preparation of the antifouling paint composition, other salts are used at the time of preparation of the antifouling paint composition. It may be formed by a reaction with a paint component.

When the antifouling coating composition of the present invention contains the monocarboxylic acid compound (D), the content thereof is preferably 1% by mass or more and 50% by mass or less, more preferably 2 in the solid content of the antifouling coating composition. It is mass% or more and 20% by mass or less, more preferably 2.5% by mass or more and 10% by mass or less, and particularly preferably 3% by mass or more and 5% by mass or less.
Further, from the viewpoint of good antifouling property and physical properties of the formed coating film, the content of the monocarboxylic acid (D) in the antifouling coating composition is the solid content of the silyl ester-based copolymer (A). It is preferably 10 parts by mass or more and 150 parts by mass or less, more preferably 12 parts by mass or more and 70 parts by mass or less, and further preferably 15 parts by mass or more and 40 parts by mass or less with respect to 100 parts by mass. If the content of the monocarboxylic acid compound (D) is too high, the polishing speed of the coating film may be excessive, especially under high temperature conditions, and if the content of the monocarboxylic acid compound (D) is low, the imidazole compound (C) may be excessive. ) May reduce the storage stability of the paint.

[Other antifouling agent (E)]
In the present invention, for the purpose of imparting antifouling property to the antifouling coating film, the antifouling coating composition of the present invention may contain other antifouling agents (E) other than the imidazole compound (C).
Other antifouling agents (E) include, for example, sulfite copper oxide, copper pyrithione, zinc pyrithione, copper thiocyanate (rodane copper), copper (metal copper), 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 traropyryl), borane-nitrogen-based base Additives (pyridinetriphenylboran, 4-isopropylpyridinediphenylmethylboran, etc.), N, N-dimethyl-N'-(3,4-dichlorophenyl) urea, N- (2,4,6-trichlorophenyl) maleimide, 2-Methylthio-4-tert-butylamino-6-cyclopropylamino-1,3,5-triazine, 2,4,5,6-tetrachloroisophthalonitrile, bisdimethyldithiocarbamoylzincethylenebisdithiocarbamate, chloro Methyl-n-octyldisulfide, N', N'-dimethyl-N-phenyl- (N-fluorodichloromethylthio) sulfamide, tetraalkylthium disulfide, zinc dimethyldithiocarbamate, zincethylenebisdithiocarbamate, 2,3-dichloro- Examples thereof include N- (2', 6'-diethylphenyl) maleimide, and 2,3-dichloro-N- (2'-ethyl-6'-methylphenyl) maleimide. In addition, the antifouling agent (E) may be used alone or in combination of two or more.
In addition, as the antifouling agent (E), it is preferable to contain cuprous oxide (E1) from the viewpoint of improving the antifouling property of the formed antifouling coating film, particularly to aquatic organisms of animal species, and water resistance.

The cuprous oxide (E1) preferably contains an average particle size of about 1 μm or more and 30 μm or less, and from the viewpoint of improving the antifouling property and water resistance of the antifouling coating film formed, the average particle size It is more preferable to include those having a diameter of 2 μm or more and 10 μm or less.
As the cuprous oxide (E1), those surface-treated with glycerin, stearic acid, lauric acid, sucrose, lecithin, mineral oil and the like are preferable from the viewpoint of long-term stability during storage.
As such cuprous oxide (E1), commercially available ones can be used, for example, NC-301 (manufactured by NC Tech Co., Ltd., average particle size: 2 μm or more and 4 μm or less), NC-803 ( NC Tech Co., Ltd., average particle size: 6 μm or more and 10 μm or less), Red Copper97N Premium (manufactured by AMERICAN CHEMET Co.), Purple Copper (manufactured by AMERICAN CHEMET Co.), LoLoTint97 (manufactured by AMERICAN CHEMET Co.), etc. Be done.

When the coating composition contains sulfite copper (E1), the content thereof is determined from the viewpoint of the coating workability of the antifouling coating composition in the present invention, the antifouling performance of the antifouling coating film, and the water resistance. The solid content of the coating composition is preferably 20% by mass or more and 80% by mass or less, more preferably 40% by mass or more and 70% by mass or less, and further preferably 50% by mass or more and 65% by mass or less.

Among the antifouling agents, it is also preferable to contain copper pyrithione from the viewpoint of improving the antifouling property of the formed antifouling coating film, particularly on aquatic micro-organisms.
When the coating composition contains copper pyrithione, the content thereof is determined from the viewpoint of the coating workability of the antifouling coating composition in the present invention, the antifouling performance of the antifouling coating film, and the water resistance of the antifouling coating composition. The solid content is preferably 0.5% by mass or more and 10% by mass or less, and more preferably 1% by mass or more and 5% by mass or less.

In addition to the above, the antifouling agent may also contain zinc pyrithione, DCOIT, tralopyryl, borane-nitrogen-based base adduct (pyridinetriphenylborane, 4-isopropylpyridinediphenylmethylborane, etc.) to prevent the antifouling coating. It is preferable because it has excellent stain resistance.

[Other binder component (F)]
In the present invention, for the purpose of imparting static antifouling property, water resistance, crack resistance and strength to the antifouling coating film, the antifouling coating composition of the present invention is other than the silyl ester-based copolymer (A). The other binder component (F) of the above may be contained.
Examples of the other binder component (F) include an acrylic copolymer (acrylic resin), a vinyl polymer, chlorinated paraffin, n-paraffin, terpenephenol, polyvinyl ethyl ether and the like. In addition, the binder component (F) may be used alone or in combination of two or more.

Examples of the acrylic copolymer include a copolymer obtained by polymerizing two or more kinds selected from the other monomer (a2), and the monomer is described from the viewpoint of static antifouling property. It is preferable to contain a structural unit derived from (a22) or a metal ester group-containing unsaturated monomer (a26).

As the other binder component (F), a commercially available product may be used, for example, "Dianal BR-106" (acrylic polymer) manufactured by Mitsubishi Chemical Corporation and "Toyoparax A-40 / A-" manufactured by Tosoh Corporation. 50 / A-70 / A-145 / A-150 ”and the like (chlorinated paraffin) can be mentioned.

In addition to the above, the other binder component (F) in the present invention includes a polymer (f1) containing two or more acid groups, for example, as described in International Publication No. 2014/010702 (hereinafter, “acid group”. Examples thereof include a polymer obtained by reacting the monocarboxylic acid compound (D) with a metal compound, which is also referred to as “containing polymer (f1)”).
Examples of such an acid group-containing polymer (f1) include a polyester-based polymer (f11) and an acrylic-based polymer (f12), and a polyester-based polymer (f11) is preferable.
As such a polyester-based polymer (f11), one having a solid acid value of 50 mgKOH / g or more and 250 mgKOH / g or less is preferable, and one having a solid content acid value of 80 mgKOH / g or more and 200 mgKOH / g or less is more preferable.
Such a polyester-based polymer (f11) can be obtained by reacting one or more polyhydric alcohols with one or more polyhydric carboxylic acids and / or anhydrides thereof, and any kind can be used in any amount. The acid value and viscosity can be adjusted by the combination.
As such a polyester-based polymer (f11), for example, a trihydric or higher alcohol (f111) is reacted with a dibasic acid and / or its anhydride (f112) and a dihydric alcohol (f113). After that, the one obtained by further reacting the alicyclic dibasic acid and / or its anhydride (f114) is preferable.
As the monocarboxylic acid compound (D) to be reacted with such a polyester-based polymer (f11), the above-mentioned compounds can be used, and among them, rosins are preferably used, and the metal compound is, for example, zinc oxide. And metal oxides such as cuprous oxide can be used, and zinc oxide is particularly preferable.

When the antifouling coating composition of the present invention contains another binder component (F), the content thereof is preferably 1% by mass or more and 20% by mass or less in the solid content of the coating composition.

[Pigment (G)]
In the present invention, the antifouling coating composition of the present invention may contain a pigment (G) for the purpose of coloring the coating film and concealing the base, and for the purpose of adjusting the coating film strength to an appropriate level. good.
Pigments (G) include, for example, talc, mica, clay, potash, zinc oxide, calcium carbonate, kaolin, alumina white, white carbon, aluminum hydroxide, magnesium carbonate, barium carbonate, barium sulfate, calcium sulfate, zinc sulfide. Includes talc, zinc oxide, petals, etc., including constitutional pigments such as petals (red iron oxide), titanium white (titanium oxide), yellow iron oxide, carbon black, naphthol red, phthalocyanine blue, etc. preferable. These pigments may be used alone or in combination of two or more.

When the antifouling coating composition of the present invention contains a pigment (G), the content thereof is a desired viscosity according to the hiding property required for the antifouling coating film to be formed, the coating form of the coating composition, and the like. The preferred amount is determined by, but the amount is preferably 1% by mass or more and 50% by mass or less in the solid content of the coating composition.

[Organic solvent (H)]
In the present invention, the antifouling coating composition may contain an organic solvent (H) for the purpose of keeping the viscosity of the coating composition low and improving the spray atomization property.
As the organic solvent (H), aromatic hydrocarbon-based, aliphatic hydrocarbon-based, alicyclic hydrocarbon-based, ketone-based, ester-based, and alcohol-based organic solvents can be used, and aromatic hydrocarbons are preferable. It is a system organic solvent.
Examples of the aromatic hydrocarbon-based organic solvent include toluene, xylene, styrene, mesitylene and the like.
Examples of the aliphatic hydrocarbon-based organic solvent include pentane, hexane, heptane, and octane.
Examples of the alicyclic hydrocarbon-based organic solvent include cyclohexane, methylcyclohexane, ethylcyclohexane and the like.
Examples of the ketone-based organic solvent include acetylacetone, acetone, methyl ethyl ketone, methyl isobutyl ketone, dimethyl carbonate and the like.
Examples of the ester-based organic solvent include propylene glycol monomethyl ether acetate and the like.
Examples of the alcohol-based organic solvent include isopropanol, n-butanol, propylene glycol monomethyl ether and the like.
The organic solvent (H) may be used alone or in combination of two or more.

When the antifouling coating composition of the present invention contains an organic solvent (H), the preferable content in the coating composition is determined by the desired viscosity according to the coating form of the coating composition and the like, but it is preferably 0. It is mass% or more and 50% by mass or less, more preferably 10% by mass or more and 40% by mass or less, and further preferably 20% by mass or more and 35% by mass or less. If the content is too high, problems such as deterioration of sagging prevention may occur.

[Sauce preventive agent / sedimentation inhibitor (I)]
In the present invention, for the purpose of adjusting the viscosity of the antifouling coating composition, the antifouling coating composition may contain a sagging inhibitor / sedimentation inhibitor (I).
Examples of the anti-sagging agent / sedimentation inhibitor (I) include organic clay waxes (stearate salts of Al, Ca, Zn, lecithin salts, etc.) and organic waxes (polyethylene wax, polyethylene oxide wax, amido wax (fatty acid amide, etc.). ), Polyamide wax, hydrogenated castor oil wax, etc.), a mixture of organic clay wax and organic wax, synthetic fine powder silica, etc.
Commercially available products may be used as the anti-sauce agent / anti-settling agent (I). 6900-20X ”,“ AS-AD-120 ”manufactured by Itoh Oil Chemicals Co., Ltd., and the like. As the anti-sauce agent / anti-settling agent (I), one type may be used alone, or two or more types may be used in combination.

When the antifouling coating composition of the present invention contains the anti-sagging agent / anti-settling agent (I), the content thereof is preferably 0.01% by mass or more and 10% by mass in the solid content of the antifouling coating composition. Hereinafter, it is more preferably 0.1% by mass or more and 3% by mass or less, and further preferably 0.5% by mass or more and 2% by mass or less.

[Dehydrating agent (J)]
In the present invention, the antifouling paint composition may contain a dehydrating agent (J) for the purpose of improving the storage stability of the paint composition.
Examples of the dehydrating agent (J) include alkoxysilane, zeolite known by the general name of "molecular sieve", porous alumina, orthoester such as orthoformate alkyl ester, orthoformic acid, and isocyanate. Among these, alkoxysilane is preferable from the viewpoint of easy availability and improvement of storage stability. These dehydrating agents may be used alone or in combination of two or more.

When the antifouling coating composition of the present invention contains a dehydrating agent (J), the content thereof is preferably 0.1% by mass or more and 10% by mass or less, more preferably 0.% by mass, based on the solid content of the coating composition. It is 2% by mass or more and 2.5% by mass or less, more preferably 0.5% by mass or more and 1.5% by mass or less. When the content of the dehydrating agent (J) is within the above range, the storage stability of the coating composition can be kept good.

[Plasticizer (K)]
The antifouling coating composition of the present invention may contain a plasticizer (K) for the purpose of imparting plasticity to the antifouling coating film.
Examples of the plasticizer (K) include tricresyl phosphate (TCP), dioctyl phthalate (DOP), diisodecyl phthalate (DIDP) and the like. These plasticizers may be used alone or in combination of two or more.

When the antifouling coating composition of the present invention contains a plasticizer (K), the content thereof is preferably 0.1% by mass or more and 10% by mass or less, more preferably 0.5 in the solid content of the coating composition. It is by mass% or more and 5% by mass or less. When the content of the plasticizer (K) is within the above range, the plasticity of the antifouling coating film can be kept good.

[Manufacturing method of antifouling paint composition]
Each of the antifouling paint compositions of the present invention can be prepared by using the same devices, means and the like as known general antifouling paints. Specifically, after preparing the silyl ester-based copolymer (A), a solution of this polymer, a sulfonic acid group-containing compound (B), and other additives as needed, are added at once or, if necessary. It can be produced by adding sequentially, stirring and mixing. Other additives may be mixed in advance in any combination, and particularly when the antifouling coating composition of the present invention contains the imidazole compound (C), the imidazole compound (C) is blended into the coating composition. And the sulfonic acid group-containing compound (B) are preferably mixed in advance.

[Anti-fouling coating film, base material with antifouling coating film and its manufacturing method, antifouling method]
The antifouling coating film of the present invention is formed from the antifouling coating composition, and is preferably obtained by drying the antifouling coating composition.
Further, the antifouling method of the present invention uses the above-mentioned antifouling coating film, and by providing an antifouling coating film using the antifouling coating composition of the present invention on various substrates. , A method of antifouling.
As a method for forming an antifouling coating film, specifically, for example, an antifouling coating film can be obtained by applying the antifouling coating composition of the present invention on a coating film or a substrate and then drying it. ..
Examples of the method for applying the coating composition of the present invention include known methods such as a method using a brush, a roller, and a spray.
The antifouling coating composition applied by the above-mentioned method is dried by leaving it at 25 ° C. for preferably about 0.5 to 14 days, more preferably about 1 to 7 days to obtain a coating film. be able to. The antifouling paint composition may be dried while being blown under heating.

The thickness of the antifouling coating film of the present invention after drying is arbitrarily selected depending on the renewal speed of the antifouling coating film, the period of use, and the like, but is preferably about 30 μm or more and 1,000 μm or less, for example. As a method for producing a coating film having this thickness, a method of applying the coating composition once to multiple times with a thickness of preferably 10 μm or more and 300 μm or less, more preferably 30 μm or more and 200 μm or less per application. Can be mentioned.

The base material with an antifouling coating film of the present invention is one in which the base material is coated with an antifouling coating film formed from the antifouling coating composition, and the base material has the antifouling coating film on the base material. Is.
The substrate with an antifouling coating film of the present invention can be produced by forming the antifouling coating film on the substrate by the method as described above.
The method for producing the base material with an antifouling coating of the present invention is not particularly limited, and for example, a step of applying or impregnating the base material with the antifouling coating composition of the present invention to obtain a coated body or an impregnated body (1-1). ), And the production method comprising the step (1-2) of drying the coated body or the impregnated body.

As the method of applying the coating composition to the substrate in the step (1-1), the above-mentioned coating method can be adopted. Further, the method of impregnation is not particularly limited, and the impregnation method can be performed by immersing the base material in a sufficient amount of the coating composition for impregnation. Further, the method for drying the coated body or the impregnated body is not particularly limited, and the coated body or the impregnated body can be dried by the same method as the method for producing the antifouling coating film.

Further, the base material with an antifouling coating film of the present invention is a step of forming an antifouling coating film by drying the antifouling coating composition of the present invention (2-1), and the coating film is attached to the base material. It can also be obtained by a production method having the step (2-2).
The method for forming the coating film in the step (2-1) is not particularly limited, and the coating film can be produced by the same method as the method for producing the antifouling coating film described above.
The method of attaching the coating film to the substrate in the step (2-2) is not particularly limited, and for example, the coating film can be attached by the method described in JP2013-129724A.

The antifouling coating composition of the present invention can be used to maintain the antifouling property of a base material for a long period of time in a wide range of industrial fields such as ships, fisheries, and marine structures. Such base materials include, for example, ships (container ships, large steel ships such as tankers, fishing ships, FRP ships, wooden ships, hull skins such as yachts, new ships or repair ships, etc.), fishing materials (ropes). , Fishing nets, fishing gear, floats, buoys, etc.), oil pipelines, water conduits, circulating water pipes, diver suits, underwater glasses, oxygen bombs, swimwear, torpedoes, underwater structures such as water supply and drainage ports of thermal and nuclear power plants, seabed Examples include cables, seawater utilization equipment (seawater pumps, etc.), megafloats, coastal roads, submarine tunnels, port facilities, and various marine civil engineering structures in canals and waterways. Among these, the base material is preferably selected from the group consisting of ships, underwater structures, and fishery materials, more preferably selected from the group consisting of ships and underwater structures, and is preferably ships. More preferred.
Further, the base material for which the antifouling coating film of the present invention is formed on the surface is a surface treated with another treatment agent such as a rust preventive agent or a surface on which a coating film such as a primer is already formed. However, the surface to which the antifouling coating composition of the present invention has already been coated may be overcoated, and the type of coating film with which the antifouling coating film of the present invention comes into direct contact is not particularly limited. do not have.
The antifouling coating film of the present invention protects against moss that easily grows in an environment affected by sunlight and gravity in water, for example, on the vertical portion of the bottom of a ship or the upper surface of a bilge keel provided between the vertical portion of the bottom and the flattening portion. Excellent stainability.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.
The "solid content" of each component used in the examples refers to the components excluding the volatile components contained as a solvent in each component, and is obtained by drying each component in a hot air dryer at 108 ° C. for 3 hours. The solvent is regarded as a solid content.

[Manufacturing of Cyril Ester-based Copolymer (A)]
<Production Example 1: Production of silyl ester-based copolymer solution (A-1)>
All reaction steps were carried out under a nitrogen stream. 53.85 parts by mass of xylene was placed in a reaction vessel equipped with a stirrer, a condenser, a thermometer, a dropping device, a nitrogen introduction tube, and a heating / cooling jacket, and heated to 80 ± 3 ° C. with stirring. While maintaining the same temperature, 50.0 parts by mass of triisopropylsilylmethacrylate, 28.0 parts by mass of methoxyethyl methacrylate, 14.0 parts by mass of methyl methacrylate, and 8.0 parts by mass of butyl acrylate were placed in the reaction vessel from the dropping device. And a monomer mixture consisting of 1.3 parts by mass of 2,2'-azobisisobutyronitrile was added dropwise over 2 hours. After that, the mixture was stirred at the same temperature for 1 hour and at 85 ° C. for 1 hour, and then raised to 105 ° C. over 3 hours while adding 0.4 parts by mass of 2,2'-azobisisobutyronitrile in 4 portions. It was warm. 12.81 parts by mass of xylene was added to the obtained reaction solution to obtain a pale yellow transparent silyl ester-based copolymer solution (A-1).
Table 1 shows the composition of the monomer mixture used, and the characteristic values of the silyl ester-based copolymer solution (A-1) and the copolymer contained therein.

<Production Examples 2 to 4: Production of Cyril Ester-based Copolymer Solutions (A-2) to (A-4)>
Similar to Production Example 1, the silyl ester-based copolymer was used in the same manner as in Production Example 1, except that the charging ratio of the monomer mixture used in Production Example 1 and the amount of the polymerization initiator used at the time of dropping were changed to the formulations (parts by mass) shown in Table 1. Polymer solutions (A-2) to (A-4) were prepared.
Table 1 shows the composition of the monomer mixture used, and the characteristic values of the silyl ester-based copolymer solutions (A-2) to (A-4) and the copolymers contained therein.

The methods for measuring the viscosities of the copolymer solutions (A-1) to (A-4), the number average molecular weight (Mn) of the copolymers contained therein, and the weight average molecular weight (Mw) are as follows.
<Viscosity of copolymer solution>
The viscosity of the copolymer solution at 25 ° C. was measured by an E-type viscometer (manufactured by Toki Sangyo Co., Ltd.).
<Measurement of number average molecular weight (Mn) and weight average molecular weight (Mw) of copolymer>
The number average molecular weight (Mn) and the weight average molecular weight (Mw) of the polymer were measured by GPC (gel permeation chromatography) under the following conditions.
GPC condition device: "HLC-8120GPC" (manufactured by Tosoh Corporation)
Column: "Super H2000 + H4000" (manufactured by Tosoh Corporation, 6 mm (inner diameter), 15 cm each (length))
Eluent: Tetrahydrofuran (THF)
Flow velocity: 0.500 ml / min
Detector: RI
Column constant temperature bath temperature: 40 ° C
Standard substance: Polystyrene Sample preparation method: The polymer solution prepared in each production example was dehydrated by adding a small amount of calcium chloride, and then filtered through a membrane filter to obtain a filter product as a GPC measurement sample.

[Examples 1 to 13, Reference Example 14, and Comparative Examples 1 to 3: Production of antifouling paint composition and antifouling coating film]
(Ingredients)
Table 2 shows each compounding component used in the antifouling paint composition.

<Manufacturing of antifouling paint composition>
With the formulations (parts by mass) shown in Table 3, each formulation component was mixed and stirred to obtain an antifouling coating composition. Further, in the antifouling coating composition containing the imidazole compound (C), the imidazole compound (C) was previously dissolved in the PGM of the component (H) and then mixed with the sulfonic acid group-containing compound (B). The mixture was used as a compounding component of the coating composition.
In addition, the compounding amount of each component shown in Table 3 shows the compounding amount in a tangible form. For example, in Example 1, the amount of fatty acid amide in the form (as a whole) is 1.5 parts by mass, and the solid content is 20%. Is 0.3 parts by mass.

<Manufacturing of antifouling coating film>
An epoxy resin-based anticorrosion paint composition (trade name "Banno 500", manufactured by China Paint Co., Ltd.) is applied to a sandblasted steel sheet (length 300 mm x width 100 mm x thickness 2.3 mm) so that the dry film thickness is 150 μm. After the coating, a vinyl resin-based binder coating composition (trade name "Silvacs SQ-K", manufactured by China Paint Co., Ltd.) was applied so that the dry film thickness was 40 μm. Subsequently, each of the antifouling coating compositions shown in Table 3 is applied once so that the dry film thickness is 200 μm, and dried under 25 ° C. conditions for 7 days to prepare a test plate with an antifouling coating film. did. The three coatings were performed once a day.
A plurality of antifouling test plates were prepared for each coating composition for use in each evaluation described later.

<Evaluation>
[Moss resistance]
The test plate with an antifouling coating film prepared as described above was immersed in Hiroshima Bay so that the test plate had an inclination of about 20 ° from the horizontal with the sea water surface and the test surface faced the sea water surface. Four months after the start of immersion under these conditions, the area of moss-like marine organisms on the antifouling coating film was measured, and the antifouling coating film was moss-resistant according to the following (moss resistance evaluation criteria). Gender was evaluated. The results are shown in Table 3.
(Moss resistance evaluation standard)
5: The area occupied by moss-like deposits on the test surface is less than 1% of the whole 4: Same as above area is 1% or more and less than 10% 3: Same as above area is 10% or more and less than 40% of the whole 2: Same as above area 40% or more and less than 70% of the whole 1: Same as above Area is 70% or more of the whole

[Barnacle resistance]
The test plate with an antifouling coating film prepared as described above was immersed in Hiroshima Bay at a position about 2 meters below the water surface so that the test surface was horizontal to the water surface and faced in the direction opposite to the water surface. Six months after the start of immersion under these conditions, the adhesion area of barnacles on the antifouling coating film was measured, and the barnacle resistance of the antifouling coating film was evaluated according to the following (barnacle resistance evaluation criteria). The results are shown in Table 3.
(Barnacle resistance evaluation criteria)
5: Area where barnacles adhered on the test surface is less than 1% of the whole 4: Same as above area is 1% or more and less than 5% 3: Same as above area is 5% or more and less than 30% of the whole 2: Same as above area is 30 of the whole % Or more and less than 70% 1: Same as above Area is 70% or more of the whole

[Paint storage stability]
The antifouling paint compositions of Examples , Reference Examples and Comparative Examples were stored at 50 ° C., the viscosities were measured at a fixed timing, the viscosities before and after storage were compared, and the results evaluated according to the following storage stability evaluation criteria were obtained. It is shown in Table 3. The viscosity of each composition was measured with a stormer viscometer (digital stormer viscometer "BROOKFIELD KU-2") under a temperature condition of 23 ° C.
(Storage stability evaluation criteria)
5: Viscosity after storage for 4 weeks is less than 130% of viscosity before storage 4: Viscosity after storage for 3 weeks is less than 130% of viscosity before storage 3: Viscosity after storage for 2 weeks is 130% of viscosity before storage Less than 2: Viscosity after 1 week storage is less than 130% of viscosity before storage 1: Viscosity after storage for 1 week is 130% or more of viscosity before storage

As is clear from the results of Examples , Reference Examples and Comparative Examples, according to the present invention, it is an antifouling coating composition capable of forming a coating film having excellent moss resistance, and when it contains the imidazole compound (C). Manufacture of an antifouling paint composition having excellent storage stability, an antifouling coating film using the same, a base material with an antifouling coating film having the same on a base material, and a base material with the antifouling coating film. A method and an antifouling method using the antifouling coating film can be provided.

Claims (10)

At least one sulfonic acid group-containing compound (B) selected from the group consisting of a silyl ester-based copolymer (A), a sulfonic acid compound, and a sulfonic acid-based polymer (however, a silyl ester-based copolymer (A). ) , And an antifouling coating composition containing the imidazole compound (C) . The silyl ester-based copolymer (A) contains a structural unit derived from a silyl (meth) acrylate represented by the following formula (I), and the formula is based on 100 parts by mass of all the structural units of the silyl ester-based copolymer. The antifouling coating composition according to claim 1, wherein the content of the structural unit derived from the silyl (meth) acrylate represented by (I) is 40 parts by mass or more and 80 parts by mass or less.

(In formula (I), R ¹ represents a hydrogen atom or a methyl group, and R ² , R ³ and R ⁴ each independently represent a monovalent hydrocarbon group.) The antifouling coating composition according to claim 1 or 2, wherein the silyl ester-based copolymer (A) is a copolymer having a structural unit derived from triisopropylsilylmethacrylate. The antifouling coating composition according to any one of claims 1 to 3, wherein the sulfonic acid group-containing compound (B) is a compound represented by the following formula (VII).

(In the formula (VII), R ³¹ represents a monovalent hydrocarbon group, and a represents an integer of 1 or more and 5 or less.) The antifouling coating composition according to any one of claims 1 to 4, wherein the silyl ester-based copolymer (A) further has a structural unit derived from a compound represented by the following formula (V).

(In formula (V), R ²⁴ represents a hydrogen atom or a methyl group, R ²⁵ represents a monovalent hydrocarbon group, R ²⁶ represents a divalent hydrocarbon group, and s is an integer of 1 or more and 30 or less. Shows.) The imidazole compound (C) is 2-methylimidazole, 4-methylimidazole, 4,5-dimethyl-1H-imidazole, (+/-) -4- [1- (2,3-dimethylphenyl) ethyl]-. The antifouling coating composition according to any one of claims 1 to 5, which is one or more selected from 1H-imidazole. An antifouling coating film formed from the antifouling coating composition according to any one of claims 1 to 6. A base material with an antifouling coating film coated with the antifouling coating film according to claim 7. The step (1-1) of applying or impregnating the antifouling coating composition according to any one of claims 1 to 6 to obtain a coated body or an impregnated body, and drying the coated body or the impregnated body. A method for producing a base material with an antifouling coating film, which comprises the step (1-2). An antifouling method using the antifouling coating film according to claim 7.