JP7803726B2 - Water-based antifouling agent composition - Google Patents

Description

The present invention relates to an aqueous antifouling composition, an antifouling coating film and a substrate with an antifouling coating film using the same, and a method for producing the aqueous antifouling composition.

Currently, antifouling compositions such as antifouling compositions for fishing nets are mainly composed of compositions containing synthetic resins such as acrylic resins. However, in recent years, in consideration of the environment, there has been a demand for antifouling compositions containing biodegradable materials.
Patent Document 1 discloses a fishing net antifouling paint composition containing a microcrystalline wax (A), a silicone oil (B), and an antifouling agent (C) for the purpose of providing a fishing net antifouling paint composition that can maintain an appropriate amount of agent release for a long period of time after immersion in water and can continuously exhibit excellent antifouling performance for a long period of time.

Japanese Patent Application Laid-Open No. 2021-85027

[0003] Usually, in order to attach a fishing net antifouling composition to a fishing net, the fishing net is immersed in the fishing net antifouling composition, which is called dyeing net, to form a coating film on the surface of the fishing net. In this case, if the viscosity of the fishing net antifouling composition is high, the coating amount (the amount adhering to the net) increases, which causes problems such as poor drying of the coating film. On the other hand, if the coating amount is insufficient, it is difficult to maintain excellent antifouling properties for a long period of time.
The fishing net antifouling paint composition described in Patent Document 1 contains microcrystalline wax, which is expected to be biodegradable, and thus reduces the environmental load, but the composition has insufficient storage stability.
If the storage stability is insufficient, the viscosity of the fishnet antifouling composition increases during the period from the production of the fishnet antifouling composition to its actual use, making the above problems likely to occur.

The present invention aims to provide an aqueous antifouling composition that has a low initial viscosity, exhibits good storage stability, and exhibits good long-term antifouling properties even when applied in a small amount, as well as a method for producing the same. A further object of the present invention is to provide an antifouling coating formed from the antifouling composition and a substrate coated with the antifouling coating.

The present inventors have conducted extensive research in light of the above-mentioned problems and have found that the above-mentioned problems can be solved by employing an antifouling composition containing a specific polyether silicone, a microcrystalline wax, polybutene, an antifouling agent, and a water-soluble organic solvent, thereby completing the present invention.
The present invention relates to the following [1] to [15].
[1] Polyether silicone (A), microcrystalline wax (B),
1. An aqueous antifouling composition comprising polybutene (C), an antifouling agent (D), and a water-soluble organic solvent (E), wherein the polyether silicone (A) is a polydimethylsiloxane in which at least one of a side chain and a terminal is modified with the following modifying group Y:

(R ^a represents a single bond or a divalent linking group, R ^b represents a hydrogen atom or a monovalent organic group having 1 to 15 carbon atoms, a and b represent integers of 1 or more, and * represents the bonding position with Si.)

[2] The aqueous antifouling composition according to [1], wherein the polyether silicone (A) is represented by the following formula (1):

(In formula (1), ^X1 and ^X2 each independently represent a hydrogen atom, an alkyl group having from 1 to 15 carbon atoms, or Y; ^X3 represents Y; R ^a represents a single bond or a divalent linking group; R ^b each represents a hydrogen atom or a monovalent organic group having from 1 to 15 carbon atoms; m, a, and b each represent an integer of 1 or more; n represents an integer of 0 or more; and * represents the bonding position with Si. However, when n is 0, ^X1 and/or ^X2 is the above-mentioned Y.)

[3] The aqueous antifouling composition according to [1] or [2], wherein the molar ratio of (poly)ethyleneoxy (EO) groups to (poly)propyleneoxy (PO) groups [EO/PO] in the polyether silicone (A) is 0.1 or more and 5.0 or less.
[4] The aqueous antifouling agent composition according to any one of [1] to [3], wherein the mass ratio of the microcrystalline wax (B) to the polyether silicone (A) [(B)/(A)] is 1.0 or more and 20.0 or less.
[5] The aqueous antifouling composition according to any one of [1] to [4], wherein the microcrystalline wax (B) is blended as a microcrystalline wax emulsion.
[6] The aqueous antifouling composition according to any one of [1] to [5], wherein the polyether silicone (A) is contained in an amount of 1 part by mass or more and 20 parts by mass or less per 100 parts by mass of the solid content of the aqueous antifouling composition.
[7] The aqueous antifouling composition according to any one of [1] to [6], containing 10 parts by mass or more and 35 parts by mass or less of the microcrystalline wax (B) per 100 parts by mass of the solid content of the aqueous antifouling composition.
[8] The aqueous antifouling composition according to any one of [1] to [7], wherein the antifouling agent (D) contains at least one selected from the group consisting of cuprous oxide, copper pyrithione, and bisdimethyldithiocarbamoylzinc ethylenebisdithiocarbamate.
[9] The aqueous antifouling composition according to any one of [1] to [8], wherein the content of one or more resins selected from the group consisting of acrylic resins and vinyl acetate resins is 3 parts by mass or less per 100 parts by mass of the solid content of the aqueous antifouling composition.
[10] The aqueous antifouling agent composition according to any one of [1] to [9], wherein the water-soluble organic solvent (E) is at least one selected from the group consisting of isopropyl alcohol, methyl cellosolve, ethyl cellosolve, propyl cellosolve, and butyl cellosolve.
[11] The aqueous antifouling composition according to any one of [1] to [10], which is for use in fishing nets.
[12] An antifouling coating formed from the aqueous antifouling composition according to any one of [1] to [11].
[13] A substrate coated with the antifouling coating according to [12].
[14] A method for producing the aqueous antifouling composition according to any one of [1] to [11], comprising the following steps 1 to 3:
Step 1: dissolving polyether silicone (A) and polybutene (C) in a water-soluble organic solvent (E) to obtain a solution; Step 2: forcibly emulsifying the solution obtained in Step 1 in an aqueous medium to obtain an emulsion; and Step 3: mixing the emulsion obtained in Step 2 with a microcrystalline wax (B) and an antifouling agent (D). [15] A method for producing the aqueous antifouling composition according to any one of [1] to [11], comprising the following Steps 1′ to 3′:
Step 1': A step of dissolving polyether silicone (A) in a water-soluble organic solvent (E) to obtain a solution. Step 2': A step of forcibly emulsifying the solution obtained in Step 1' in an aqueous medium to obtain an emulsion. Step 3': A step of mixing the emulsion obtained in Step 2' with microcrystalline wax (B), polybutene (C), and an antifouling agent (D).

The present invention provides an aqueous antifouling composition that has a low initial viscosity, exhibits good storage stability, and exhibits good long-term antifouling properties even when applied in a small amount, as well as a method for producing the same. The present invention also provides an antifouling coating formed from the antifouling composition and a substrate coated with the antifouling coating.

The following provides a detailed description of the aqueous antifouling composition of the present invention, its production method, an antifouling coating using the aqueous antifouling composition, and a substrate coated with an antifouling coating.

[Water-based antifouling composition]
The aqueous antifouling composition of the present invention (hereinafter also referred to as "antifouling composition" or "composition") contains polyether silicone (A), microcrystalline wax (B), polybutene (C), an antifouling agent (D), and a water-soluble organic solvent (E), wherein the polyether silicone (A) is a polydimethylsiloxane in which at least one of a side chain and an end is modified with the following modifying group Y. In the following description, "the aqueous antifouling composition of the present invention" will also be referred to as "the present composition."

(R ^a represents a single bond or a divalent linking group, R ^b represents a hydrogen atom or a monovalent organic group having 1 to 15 carbon atoms, a and b represent integers of 1 or more, and * represents the bonding position with Si.)

According to the present invention, there is provided a water-based antifouling composition which has a low initial viscosity, exhibits good storage stability, and further exhibits good long-term antifouling properties even when the coating amount is small.
If the storage stability is insufficient, the viscosity of the aqueous antifouling composition increases between the time of its production and the time of its actual use. For example, when used as an antifouling composition for fishing nets, the amount of the aqueous antifouling composition applied to the fishing net increases, resulting in a problem of poor drying properties. Furthermore, if the amount of the aqueous antifouling composition applied can be reduced, not only will the drying properties be improved, but the amount of the aqueous antifouling composition used can be reduced, which is also advantageous in terms of cost. Therefore, there is a need for the development of an antifouling composition for fishing nets that can exhibit long-term antifouling properties even when the amount applied is small.
Although the detailed reasons why this composition achieves the above-mentioned effects are unclear, it is believed to be as follows. It is believed that the use of a polydimethylsiloxane modified with a modifying group having both an ethyleneoxy group and a propyleneoxy group as the polyether silicone (A), and the forced emulsification of this polyether silicone (A) using a water-soluble organic solvent (E), resulted in a low initial viscosity and good storage stability. Here, the ethyleneoxy group contributes significantly to storage stability, while the propyleneoxy group contributes significantly to reducing the initial viscosity. Therefore, it is believed that the use of a polyether silicone modified with a modifying group having both an ethyleneoxy group and a propyleneoxy group can achieve both a reduced initial viscosity and improved storage stability. Furthermore, it is believed that the inclusion of a microcrystalline wax (B), a plasticizer polybutene (C), and an antifouling agent (D) allows for good long-term antifouling properties to be achieved even with a small coating weight.
Each component contained in the aqueous antifouling composition will be described below.

[Polyether silicone (A)]
The present composition contains a polyether silicone (A), and the polyether silicone (A) has been modified at least at one of its side chains and its terminals with a modifying group Y described below.
That is, the polyether silicone (A) has both a (poly)ethyleneoxy group and a (poly)propyleneoxy group. The propyleneoxy group may be either linear or branched, and is not particularly limited.

(R ^a represents a single bond or a divalent linking group, R ^b represents a hydrogen atom or a monovalent organic group having 1 to 15 carbon atoms, a and b represent integers of 1 or more, and * represents the bonding position with Si.)

The above R ^a represents a single bond or a divalent linking group, and a preferred example of the divalent linking group is an alkylene group. When ^{R a} is an alkylene group, the alkylene group preferably has 1 or more carbon atoms, more preferably 2 or more carbon atoms, and preferably 20 or less, more preferably 12 or less, and even more preferably 6 or less carbon atoms.
^Rb represents a hydrogen atom or a monovalent organic group having from 1 to 15 carbon atoms, which may contain oxygen atoms and nitrogen atoms in addition to carbon and hydrogen atoms, and some or all of the hydrogen atoms may be substituted with halogen atoms. ^Rb is preferably a hydrogen atom, a hydrocarbon group having from 1 to 6 carbon atoms, or an acyl group (-C(=O) _-CH3 ), more preferably a hydrogen atom, an alkyl group having from 1 to 6 carbon atoms, or an acyl group.

a represents an integer of 1 or more, preferably an integer of 3 or more, and is preferably an integer of 50 or less, more preferably an integer of 40 or less, and even more preferably an integer of 30 or less.
b represents an integer of 1 or more, preferably an integer of 3 or more, and is preferably an integer of 50 or less, more preferably an integer of 40 or less, and even more preferably an integer of 30 or less.
The average value of a is 1 or more, preferably 3 or more, and is preferably 50 or less, more preferably 40 or less, and further preferably 30 or less.
Similarly, the average value of b is 1 or more, preferably 3 or more, and is preferably 50 or less, more preferably 40 or less, and even more preferably 30 or less.
The (poly)ethyleneoxy groups and (poly)propyleneoxy groups may be present randomly in the modifying group Y, or the (poly)ethyleneoxy groups and (poly)propyleneoxy groups may be present in blocks, and are not particularly limited.
The number of moles of ethyleneoxy groups added per mole of polyether silicone (A) is preferably 1 or more, more preferably 3 or more, even more preferably 5 or more, and is preferably 50 or less, more preferably 40 or less, even more preferably 30 or less.
The number of moles of propyleneoxy groups added per mole of polyether silicone (A) is preferably 1 or more, more preferably 3 or more, even more preferably 5 or more, and is preferably 50 or less, more preferably 40 or less, even more preferably 30 or less.
The number of moles of ethyleneoxy groups or propyleneoxy groups added per mole of polyethersilicone (A) refers to the sum of the ethyleneoxy groups or propyleneoxy groups at both ends when the polyethersilicone (A) is modified, for example, at both ends with modifying group Y. When the polyethersilicone (A) is modified with multiple types of modifying group Y, the number of moles added refers to the total number of moles added.

The polyether silicone (A) is preferably a compound represented by the following formula (1):

(In formula (1), ^X1 and ^X2 each independently represent a hydrogen atom, an alkyl group having from 1 to 15 carbon atoms, or Y; ^X3 represents Y; R ^a represents a single bond or a divalent linking group; R ^b each represents a hydrogen atom or a monovalent organic group having from 1 to 15 carbon atoms; m, a, and b each represent an integer of 1 or more; n represents an integer of 0 or more; and * represents the bonding position with Si. However, when n is 0, ^X1 and/or ^X2 is the above-mentioned Y.)

In formula (1), R ^a , R ^b , a, and b are the same as R ^a , R ^b , a, and b in the modifying group Y described above, and the preferred ranges are also the same.
In formula (1), ^X1 and ^X2 each independently represent a hydrogen atom, an alkyl group having 1 to 15 carbon atoms, or Y. The number of carbon atoms in the alkyl group is preferably 1 to 12, more preferably 1 to 6, even more preferably 1 to 3, and still more preferably 1, i.e., a methyl group. ^X1 and ^X2 are particularly preferably a methyl group or Y.
m represents an integer of 1 or more, preferably an integer of 3 or more, more preferably an integer of 5 or more, and is preferably an integer of 1000 or less, more preferably an integer of 500 or less, and even more preferably an integer of 100 or less.
n represents an integer of 0 or more, preferably an integer of 100 or less, more preferably an integer of 70 or less, even more preferably an integer of 40 or less, and still more preferably an integer of 20 or less.

The average value of m in the polyether silicone (A) represented by formula (1) is preferably 3 or more, more preferably 5 or more, even more preferably 10 or more, and is preferably 1,000 or less, more preferably 500 or less, even more preferably 100 or less.
Similarly, the average value of n is 0 or more, and preferably 100 or less, more preferably 70 or less, even more preferably 40 or less, and still more preferably 20 or less.

In formula (1), when n is 0, that is, when there is no modifying group Y in the side chain, ^X1 and/or ^X2 is the above-mentioned modifying group Y. At least one of ^X1 and ^X2 may be the modifying group Y.

The polyether silicone (A) may be in any of the following forms (1) to (4):
(1) The modifying group Y is present only in the side chain.
In this case, X ¹ and X ² are each independently a hydrogen atom or an alkyl group having 1 to 15 carbon atoms, and n is an integer of 1 or more.
(2) The modified group Y is present at only one end.
In this case, one of ^X1 and ^X2 is the modifying group Y, and the other is a hydrogen atom or an alkyl group having 1 to 15 carbon atoms.
(3) The modified group Y is present only at both ends.
In this case, ^X1 and ^X2 are the modifying group Y and n=0.
(4) The compound has a modifying group Y on the side chain and at the end.
In this case, at least one of ^X1 and ^X2 is a modifying group Y, and n is an integer of 1 or more.
Among these, the polyether silicone (A) is preferably embodiment (1) or (3), more preferably embodiment (3).

The molar ratio [EO/PO] of ethyleneoxy (EO) groups to propyleneoxy (PO) groups in the polyether silicone (A), i.e., a/b in the modifying group Y, is preferably 0.1 or more, and is preferably 5.0 or less, more preferably 2.0 or less, even more preferably 1.0 or less, and still more preferably 0.8 or less, from the viewpoint of obtaining a composition that has a low initial viscosity, excellent storage stability, and excellent long-term antifouling properties even with a small coating amount.
The molar ratio of EO groups to PO groups in the polyether silicone (A) can be measured, for example, by ¹ H NMR measurement.

From the viewpoints of reducing the initial viscosity, antifouling properties, and coating workability of the composition, the kinematic viscosity of the polyether silicone (A) at 25°C is preferably 10 mm ² /s or more, more preferably 50 mm ² /s or more, and even more preferably 100 mm ² /s or more, and is preferably 5000 mm ² /s or less, more preferably 2000 mm ² /s or less, and even more preferably 500 mm ² /s or less.
The kinematic viscosity of the polyether silicone (A) is measured by the method described in the examples.

Polyether silicone (A) can be obtained by conventional methods, such as by subjecting an organopolysiloxane containing ≡SiH groups to an addition reaction in the presence of a platinum catalyst with a polyoxyalkylene compound having unsaturated groups such as vinyl groups or allyl groups, and ethyleneoxy groups or propyleneoxy groups at the molecular chain terminals, or by subjecting an organopolysiloxane to a dehydrogenation reaction with a polyoxyalkylene compound having hydroxyl groups, ethyleneoxy groups or propyleneoxy groups at the molecular chain terminals. References include JP-A-2-302438. Commercially available products can also be used.

From the viewpoint of obtaining a composition that has a low initial viscosity, excellent storage stability, and excellent long-term stain resistance even when applied in a small amount, the content of polyether silicone (A) in the solids of the composition is preferably at least 1 part by mass, more preferably at least 3 parts by mass, even more preferably at least 5 parts by mass, and preferably at most 20 parts by mass, more preferably at most 15 parts by mass, even more preferably at most 10 parts by mass.

[Microcrystalline wax (B)]
Microcrystalline wax (B) is a wax that is solid at room temperature and is separated from the vacuum distillation bottoms during petroleum refining. It has a carbon number of approximately 30 to 60, a molecular weight of approximately 500 to 1000, and generally has a higher melting point than paraffin wax. Furthermore, microcrystalline wax (B) has a microcrystalline structure due to the large amount of small crystalline isoparaffins and cycloparaffins in its composition. This microcrystalline structure imparts flexibility to the coating film formed and has the effect of improving adhesion to the substrate.

The melting point of the microcrystalline wax (B) is not particularly limited, but is preferably 60°C or higher and 105°C or lower, and more preferably 77°C or higher and 88°C or lower. The melting point is measured based on the melting point test method described in JIS K 2235-5.3:1991.

Microcrystalline wax (B) can be appropriately selected from commercially available products, such as the Hi-Mic series (Hi-Mic-1090, Hi-Mic-1080, Hi-Mic-1070, etc.) manufactured by Nippon Seiro Co., Ltd.

The microcrystalline wax (B) is preferably blended into the present composition as a microcrystalline wax emulsion, and commercially available products may be used as the microcrystalline wax emulsion.
The microcrystalline wax emulsion preferably has resistance to water-soluble organic solvents. Here, resistance to water-soluble organic solvents means that the emulsion state is maintained even when the water-soluble organic solvent (E) is added to the microcrystalline wax emulsion.

From the viewpoint of obtaining a composition that has low initial viscosity, excellent storage stability, and excellent long-term stain resistance even with a small coating amount, the content of microcrystalline wax (B) per 100 parts by mass of the solids content of the composition is preferably 10 parts by mass or more, more preferably 15 parts by mass or more, even more preferably more than 20 parts by mass, still more preferably 22 parts by mass or more, and preferably 35 parts by mass or less, more preferably 33 parts by mass or less, and even more preferably 31 parts by mass or less.

The mass ratio of the microcrystalline wax (B) to the polyether silicone (A) in the composition [(B)/(A)] is preferably 1.0 or more, more preferably 2.0 or more, even more preferably 3.0 or more, and is preferably 20.0 or less, more preferably 15.0 or less, even more preferably 10.0 or less.
Furthermore, the total content of the polyether silicone (A) and the microcrystalline wax (B) [(A) + (B)] per 100 parts by mass of the solid content of the composition is preferably 12% by mass or more, more preferably 20% by mass or more, even more preferably 25% by mass or more, and is preferably 70% by mass or less, more preferably 65% by mass or less, even more preferably 60% by mass or less.
When [(B)/(A)] is from 1.0 to 20.0 and [(A)+(B)] is from 12 to 70 mass %, separation of the polyether silicone (A) in the composition is suppressed, and a composition can be obtained which has a low initial viscosity, excellent storage stability, and excellent long-term antifouling properties even with a small coating amount, which is therefore preferred.

[Polybutene (C)]
Examples of the polybutene (C) include polybutene and polyisobutene.
As the polybutene (C), commercially available products can be used, such as polybutene LV-7, polybutene LV-10, polybutene LV-25, polybutene LV-50, polybutene LV-100, polybutene HV-35, polybutene HV-100, polybutene HV-300, and polybutene HV-1900 (all manufactured by ENEOS Corporation); polybutene 0N, polybutene 06N, and polybutene 10N (all manufactured by NOF Corporation).
The polybutene (C) may be added in the form of a polybutene emulsion, and examples of the polybutene emulsion include Emawet 10E, Emawet 10H, Emawet 30E, and Emawet 30H (all manufactured by NOF Corporation).

The content of polybutene (C) per 100 parts by mass of the solid content of the composition, calculated on a solid content basis, is preferably 1 part by mass or more, more preferably 5 parts by mass or more, even more preferably 8 parts by mass or more, and is preferably 20 parts by mass or less, more preferably 16 parts by mass or less, even more preferably 12 parts by mass or less, from the viewpoint of obtaining a composition that has low initial viscosity, excellent storage stability, and excellent long-term stain resistance even with a small coating amount.

[Anti-fouling agent (D)]
The present composition contains an antifouling agent (D) for the purpose of enhancing antifouling properties.
The antifouling agent (D) is eluted from the antifouling coating in water and has the effect of inhibiting aquatic organisms from attaching to the surface of the antifouling coating, thereby improving the antifouling properties.
The antifouling agent (D) may be either an inorganic or organic antifouling agent, and is preferably one that has a repellent effect on aquatic organisms and has a certain dissolution rate into water.
Examples of inorganic antifouling agents include copper or copper compounds (excluding pyrithione compounds) such as cuprous oxide, metallic copper powder, and cuprous thiocyanate (copper rhodanide), of which cuprous oxide and cuprous thiocyanate (copper rhodanide) are preferred, and cuprous oxide is more preferred.

Organic antifouling agents include:
Metal pyrithiones (pyrithione compounds) such as copper pyrithione and zinc pyrithione;
tetraalkylthiuram disulfides such as tetramethylthiuram disulfide;
Carbamate compounds such as zinc dimethyldithiocarbamate, zinc ethylenebisdithiocarbamate, and bisdimethyldithiocarbamoylzinc ethylenebisdithiocarbamate;
Maleimide compounds such as 2,4,6-trichlorophenylmaleimide, 2,3-dichloro-N-(2',6'-diethylphenyl)maleimide, and 2,3-dichloro-N-(2'-ethyl-6'-methylphenyl)maleimide;
2,4,5,6-tetrachloroisophthalonitrile, N,N-dimethyldichlorophenylurea, 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one, 2-methylthio-4-tert-butylamino-6-cyclopropyl-S-triazine, chloromethyl-n-octyl disulfide, N',N'-dimethyl-N-phenyl-(N-fluorodichloromethylthio)sulfamide, N',N'-dimethyl-N-tolyl-(N-fluorodichloromethylthio)sulfamide;
Amine-organoborane complexes such as triphenyl[3-(2-ethylhexyloxy)propylamine]boron, triphenyl(n-octadecylamine)boron, pyridinetriphenylborane, and 4-isopropylpyridinediphenylmethylborane;
(+/-)-4-[1-(2,3-dimethylphenyl)ethyl]-1H-imidazole (medetomidine);
4-bromo-2-(4-chlorophenyl)-5-(trifluoromethyl)-1H-pyrrole-3-carbonitrile (tralopyril);
Examples include:
Among these, preferred organic antifouling agents are copper pyrithione, zinc pyrithione, bisdimethyldithiocarbamoylzinc ethylenebisdithiocarbamate, 2-methylthio-4-tert-butylamino-6-cyclopropyl-S-triazine and (+/-)-4-[1-(2,3-dimethylphenyl)ethyl]-1H-imidazole (medetomidine), more preferred are copper pyrithione, bisdimethyldithiocarbamoylzinc ethylenebisdithiocarbamate and (+/-)-4-[1-(2,3-dimethylphenyl)ethyl]-1H-imidazole (medetomidine), and even more preferred are copper pyrithione and bisdimethyldithiocarbamoylzinc ethylenebisdithiocarbamate.

The antifouling agent (D) may be used alone or in combination of two or more kinds.
The antifouling agent (D) preferably contains at least one selected from the group consisting of cuprous oxide, copper pyrithione, and bisdimethyldithiocarbamoylzinc ethylenebisdithiocarbamate. Use of these antifouling agents is preferred because it allows a composition with excellent long-term antifouling properties to be obtained even with a small coating amount.

From the viewpoint of providing a composition with excellent long-term stain resistance even at low coating weights, and from the viewpoint of maintaining the viscosity of the composition in an appropriate range, the content of the antifouling agent (D) is preferably at least 5 parts by mass, more preferably at least 20 parts by mass, even more preferably at least 35 parts by mass, and even more preferably at least 45 parts by mass, per 100 parts by mass of the solids content of the composition, and is preferably at most 80 parts by mass, more preferably at most 70 parts by mass, and even more preferably at most 60 parts by mass.

[Water-soluble organic solvent (E)]
The composition contains a water-soluble organic solvent (E).
The water-soluble organic solvent (E) is a hydrophilic organic solvent and has a solubility of 10 g or more in 100 g of water at 20° C. The water-soluble organic solvent (E) is preferably compatible with water.
Examples of the water-soluble organic solvent (E) include alcohols, cellosolves, ketones, glycols, ethers, amides, carbonates, and other polar solvents.
Alcohols such as methanol, ethanol, n-propanol, isopropyl alcohol, n-butanol, and isobutanol;
Cellosolves such as methyl cellosolve, ethyl cellosolve, propyl cellosolve, butyl cellosolve, and cellosolve acetate;
ketones such as acetone and methyl ethyl ketone;
Glycols such as ethylene glycol, propylene glycol, glycerin, and 1,3-butanediol;
Ethers such as diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, triethylene glycol monobutyl ether, tetraethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dipropylene glycol dimethyl ether, carbitol, dioxane, tetrahydrofuran, and 3-methoxy-3-methyl-1-butanol;
amides such as dimethylformamide, dimethylacetamide, pyrrolidone, N-methylpyrrolidone, 3-methoxy-N,N-dimethylpropanamide, and 3-butoxy-N,N-dimethylpropanamide;
Carbonates such as ethylene carbonate, propylene carbonate, and dimethyl carbonate;
Other polar solvents such as dimethyl sulfoxide, tetramethyl urea, dimethyl imidazolidinone, etc.;
These may be used alone or in combination of two or more.
Among these, from the viewpoint of being a good solvent for the polyether silicone (A) and being suitable as a solvent for forced emulsification, the water-soluble organic solvent (E) is preferably selected from cellosolves and alcohols, and more preferably at least one selected from the group consisting of isopropyl alcohol, methyl cellosolve, ethyl cellosolve, propyl cellosolve, and butyl cellosolve.

There are no particular restrictions on the content of the water-soluble organic solvent (E) in the composition, but from the perspective that it is preferable to use it as a solvent when forcibly emulsifying the polyether silicone (A), it is preferably 1.0% by mass or more, more preferably 2.0% by mass or more, even more preferably 2.5% by mass or more, and is preferably 20.0% by mass or less, more preferably 15.0% by mass or less, even more preferably 10.0% by mass or less.
Furthermore, when an emulsion containing polyethersilicone (A) and polybutene (C) is obtained by dissolving polyethersilicone (A) and polybutene (C) in a water-soluble organic solvent (E) and forcibly emulsifying them, as described below, the content of the water-soluble organic solvent (E) is preferably at least 10 parts by mass, more preferably at least 30 parts by mass, and even more preferably at least 50 parts by mass, per 100 parts by mass of the total mass of the polyethersilicone (A) and polybutene (C), and is preferably at most 1000 parts by mass, more preferably at most 300 parts by mass, and even more preferably at most 150 parts by mass.
Furthermore, when an emulsion containing polyethersilicone (A) is obtained by forcibly emulsifying only polyethersilicone (A) by dissolving it in a water-soluble organic solvent (E) as described below, the content of water-soluble organic solvent (E) is preferably at least 10 parts by mass, more preferably at least 30 parts by mass, and even more preferably at least 50 parts by mass, per 100 parts by mass of polyethersilicone (A), and is preferably at most 1000 parts by mass, more preferably at most 300 parts by mass, and even more preferably at most 150 parts by mass.

〔water〕
The composition contains water as the main solvent component.
The water is not particularly limited, and well water, tap water, ion-exchanged water, distilled water, etc. can be used.
The content of water in the entire solvent including the water-soluble organic solvent (E) is 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, and still more preferably 85% by mass or more, from the viewpoint of reducing the environmental load, suppressing problems with VOCs (volatile organic compounds), and maintaining the viscosity of the composition in an appropriate range and the coating amount in an appropriate range. Furthermore, from the viewpoint of maintaining the content of the water-soluble organic solvent (E) in an appropriate range, the content of water is preferably 99% by mass or less, more preferably 98% by mass or less, and even more preferably 96% by mass or less.
Furthermore, from the viewpoint of maintaining the viscosity of the composition in an appropriate range, maintaining the coating amount in an appropriate range, and facilitating drying of the composition, the water content in the composition is preferably 20% by mass or more, more preferably 30% by mass or more, even more preferably 40% by mass or more, and still more preferably 50% by mass or more, and is preferably 90% by mass or less, more preferably 80% by mass or less, and even more preferably 70% by mass or less.

In addition to the above-mentioned components (A) to (E) and water, the composition may contain other components. Examples of other components include color pigments (F), anti-sagging/anti-settling agents (G), surfactants (antifoaming agents (H), dispersants/emulsifiers (I), etc.), and spreading resins (J).

[Coloring pigment (F)]
The composition also preferably contains a color pigment (F).
By including the color pigment (F) in the present composition, the coating strength can be increased.
The color pigment (F) is not particularly limited, and examples thereof include inorganic pigments such as iron oxide, titanium oxide, carbon black, zinc oxide, aluminum silicate, alumina white, and barium sulfate; and organic pigments such as naphthol red and phthalocyanine blue. From the viewpoints of the production workability and coating workability of the composition, storage stability, and the antifouling properties of the antifouling coating, inorganic pigments are preferred, and among these, one or more pigments selected from iron oxide, titanium oxide, carbon black, zinc oxide, aluminum silicate, alumina white, and barium sulfate are preferred, one or more pigments selected from iron oxide, titanium oxide, and carbon black are more preferred, and carbon black is even more preferred.
Examples of iron oxide include red iron oxide, yellow iron oxide, and black iron oxide.
As titanium oxide, any of rutile, anatase and brookite types can be used, and from the viewpoints of the stability of the antifouling coating and composition and ease of availability, it is preferable to use the rutile type.

When the composition contains a color pigment (F), the content of the color pigment (F) per 100 parts by mass of the solids content of the composition is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, even more preferably 0.1% by mass or more, still more preferably 0.15% by mass or more, and preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 10% by mass or less, from the viewpoints of the antifouling properties of the antifouling coating, the ease of manufacturing and coating the composition, low initial viscosity, and excellent storage stability.

[Anti-sagging and anti-settling agents (G)]
The present composition may contain an anti-sagging agent/anti-settling agent (G) for the purpose of adjusting the viscosity of the composition, etc.
When the present composition contains an anti-sagging agent/anti-settling agent (G), the anti-sagging agent/anti-settling agent (G) may be used alone or in combination of two or more types.

Examples of anti-sagging/anti-settling agents (G) include inorganic anti-settling agents such as bentonite clay and hectorite clay, organic clay waxes (e.g., stearate salts of Al, Ca, and Zn, lecithin salts, and alkyl sulfonates), organic waxes (e.g., polyethylene wax, oxidized polyethylene wax, amide wax, polyamide wax, and hydrogenated castor oil wax), mixtures of organic clay waxes and organic waxes, and synthetic finely powdered silica.

Commercially available anti-sagging and anti-settling agents (G) may be used. Examples of such commercially available products include AQ-600, AQ-630, and AQ-870 (all manufactured by Kusumoto Chemical Co., Ltd.), Thixol W-400LP (Kyoeisha Chemical Co., Ltd.), Bentone HD (manufactured by Elementis Specialtes, Inc.), and Aerosil No. 200 (manufactured by Nippon Aerosil Co., Ltd.).

When the composition contains an anti-sagging/anti-settling agent (G), the content thereof is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, even more preferably 1% by mass or more, and preferably 10% by mass or less, more preferably 5% by mass or less, even more preferably 3% by mass or less, based on 100 parts by mass of the solid content of the composition.

The composition may contain a surfactant. The surfactant is also called an antifoaming agent (H) or a dispersant/emulsifier (I) depending on the purpose and effect.
[Antifoaming agent (H)]
The present composition may contain an antifoaming agent (H) for the purposes of improving the ease of production and application of the composition and improving the strength and antifouling properties of the antifouling coating film that is formed.
As the antifoaming agent (H), fluorine-based, silicone-based, acrylic-based, etc. antifoaming agents may be used. Two or more types of antifoaming agents (H) may be used in combination.
As the antifoaming agent (H), commercially available products can be used, such as "BYK-011" and "BYK-012" manufactured by BYK Japan KK.
When the composition contains a defoaming agent (H), the content of the defoaming agent (H) relative to 100 parts by mass of the solid content of the composition is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, even more preferably 0.1% by mass or more, and is preferably 5% by mass or less, more preferably 2% by mass or less, even more preferably 0.5% by mass or less.

[Dispersant/Emulsifier (I)]
The present composition may contain a dispersant/emulsifier (I), and preferably contains a dispersant/emulsifier (I) in order to improve the dispersibility of the color pigment (F), polyether silicone (A), microcrystalline wax (B), etc. in the composition and to emulsify them.
Examples of the dispersant/emulsifier (I) include nonionic surfactants and anionic surfactants. Examples of the nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene oxypropylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene oxypropylene alkyl phenyl ethers, polyoxyethylene distyryl phenyl ethers, polyoxyethylene oxypropylene distyryl phenyl ethers, and polyoxyethylene tristyryl phenyl ethers, and two or more of these may be used in combination.
Examples of anionic surfactants include sulfate ester salts and phosphate ester salts of nonionic surfactants, polyoxyethylene alkyl ether carboxylate salts, alkylbenzene sulfonates, and alkylnaphthalene sulfonates, and two or more of these may be used in combination.

Furthermore, a polymer dispersant may be used as the dispersant/emulsifier (I). Examples of polymer dispersants include (meth)acrylic resins and salts thereof, such as poly(meth)acrylic acid, (meth)acrylic acid-acrylonitrile copolymer, (meth)acrylic acid-(meth)acrylic acid ester copolymer, vinyl acetate-(meth)acrylic acid ester copolymer, vinyl acetate-(meth)acrylic acid copolymer, and vinylnaphthalene-(meth)acrylic acid copolymer; styrene-(meth)acrylic acid copolymer, styrene-(meth)acrylic acid-(meth)acrylic acid ester copolymer, styrene-α-methylstyrene-(meth)acrylic acid copolymer, and styrene-α-methylstyrene-(meth)acrylic acid copolymer. ) Styrenic resins such as acrylic acid-(meth)acrylic acid ester copolymer, styrene-maleic acid copolymer, and styrene-maleic anhydride copolymer, and their salts; urethane resins and their salts, which are polymeric compounds (resins) containing urethane bonds formed by the reaction of an isocyanate group and a hydroxyl group, and which are linear and/or branched and may or may not have a crosslinked structure; polyvinyl alcohols; vinyl naphthalene-maleic acid copolymers and their salts; vinyl acetate-maleic acid ester copolymers and their salts; and water-soluble resins such as vinyl acetate-crotonic acid copolymers and their salts.

As the dispersant/emulsifier (I), known products may be used, such as DISPER BYK-187, DISPER BYK-190, DISPER BYK-191, DISPER BYK-194N, and DISPER BYK-199 (manufactured by BYK-Chemie Co., Ltd.), Aron A-210 and A6114 (manufactured by Toagosei Co., Ltd.), and DKS-NL100 (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.).

The content of dispersant/emulsifier (I) per 100 parts by mass of the solid content of the composition is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, even more preferably 0.15 parts by mass or more, and preferably 5 parts by mass or less, more preferably 3 parts by mass or less, even more preferably 1 part by mass or less.

[Spreadable resin (J)]
The composition may contain a spreading resin (J). The spreading resin is used to promote film formation. Note that the spreading resin (J) does not include the above-mentioned polyether silicone (A), microcrystalline wax (B), or polybutene (C).
Examples of the spreading resin (J) include synthetic resins such as acrylic resins, vinyl acetate resins (e.g., ethylene-vinyl acetate copolymers), epoxy ester resins, urethane resins, alkyd resins, polyester resins, synthetic rubbers, and chlorinated polyethylene; natural resins such as wood rosin, gum rosin, and modified rosin; and modified products of these resins, and these can be used alone or in combination of two or more.
Such a spreading resin (J) is used in the form of an emulsion, dispersion, or aqueous solution.

In the present composition, the content of spreading resin (J) is preferably small from the viewpoint of reducing the initial viscosity of the composition and from the viewpoint of storage stability, and is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, even more preferably 3 parts by mass or less, and even more preferably 1 part by mass or less, per 100 parts by mass of the solid content of the present composition.
In particular, when the spreading resin (J) is at least one selected from the group consisting of acrylic resins and vinyl acetate resins, the storage stability of the composition tends to decrease, and the total content of acrylic resin and vinyl acetate resin per 100 parts by mass of the solid content of the composition is preferably 3 parts by mass, more preferably 1 part by mass or less, and even more preferably substantially free. Note that "substantially free" means that acrylic resin and vinyl acetate resin are not intentionally added, and that the total content of acrylic resin and vinyl acetate resin per 100 parts by mass of the solid content of the composition is 0.5 parts by mass or less, preferably 0.1 parts by mass or less.

[Viscosity of Composition]
The viscosity of the composition at 23°C, measured in accordance with ASTM D1200 using a Ford Cup No. 4, is preferably 8 seconds or more, more preferably 9 seconds or more, and even more preferably 10 seconds or more, from the viewpoint of reducing the coating amount and facilitating drying, particularly when used as an aqueous antifouling composition for fishing nets, and from the viewpoint of ease of application, when used as an aqueous antifouling coating composition, and is preferably 40 seconds or less, more preferably 20 seconds or less, and even more preferably 15 seconds or less.
It is preferable that the initial viscosity and the viscosity after storage at 40°C for one month satisfy the above ranges.

[Storage stability]
The composition has excellent storage stability, and the difference in viscosity at 23°C measured using a Ford Cup No. 4 in accordance with ASTM D1200 before and after storage at 40°C for one month is preferably +2 seconds or less, more preferably +1 second or less.
Specifically, the viscosity is measured by the method described in the Examples.

[Method for preparing aqueous antifouling composition]
The method for preparing the present composition is not particularly limited as long as it is possible to prepare a composition containing the above-described components. However, it is preferable that the method be a method including the following steps 1 to 3 (Method 1) or a method including the following steps 1' to 3' (Method 2).
In the case of Method 2, it is preferable to add the polybutene (C) in the form of a polybutene emulsion in Step 3'.
<Method 1>
A method for producing an aqueous antifouling composition, comprising the following steps 1 to 3:
Step 1: A step of dissolving polyether silicone (A) and polybutene (C) in a water-soluble organic solvent (E) to obtain a solution; Step 2: A step of forcibly emulsifying the solution obtained in Step 1 in an aqueous medium to obtain an emulsion; Step 3: A step of mixing the emulsion obtained in Step 2 with a microcrystalline wax (B) and an antifouling agent (D) <Method 2>
A method for producing an aqueous antifouling composition, comprising the following steps 1' to 3':
Step 1': A step of dissolving polyether silicone (A) in a water-soluble organic solvent (E) to obtain a solution. Step 2': A step of forcibly emulsifying the solution obtained in Step 1' in an aqueous medium to obtain an emulsion. Step 3': A step of mixing the emulsion obtained in Step 2' with microcrystalline wax (B), polybutene (C), and an antifouling agent (D).

In the above methods 1 and 2, an emulsion is obtained by dissolving polyether silicone (A) in a water-soluble organic solvent (E) and forcibly emulsifying the solution. This makes it possible to produce an emulsion of polyether silicone (A) without using a dispersant or emulsifier (I), which is preferable because it results in a composition with a lower initial viscosity and excellent storage stability.

The aqueous medium used in step 2 and step 2' contains water as the main component, and may contain the above-mentioned water-soluble organic solvent (E).
The water content in the aqueous medium is preferably 50% by mass or more, more preferably 70% by mass or more, even more preferably 90% by mass or more, and 100% by mass or less, even more preferably 100% by mass or less. In other words, it is preferable to use only water.

Furthermore, from the viewpoint of antifouling properties and paint properties, it is preferable that the aqueous medium in Steps 2 and 2' does not contain a dispersant/emulsifier (I). The content of dispersant/emulsifier (I) in the aqueous medium is preferably 1% by mass or less, more preferably 0.3% by mass or less, even more preferably 0.1% by mass or less, and it is even more preferable that the aqueous medium is substantially free of dispersant/emulsifier (I).

In steps 1 and 1', the temperature during dissolution is preferably 5°C or higher, more preferably 10°C or higher, even more preferably 15°C or higher, and preferably 40°C or lower, more preferably 35°C or lower, even more preferably 30°C or lower.

In steps 2 and 2', a high-speed stirring homogenizer such as Homo Disper 2.5 (manufactured by Primix Corporation) can be used for forced emulsification, and the temperature during forced emulsification is preferably 5°C or higher, more preferably 10°C or higher, even more preferably 15°C or higher, and preferably 40°C or lower, more preferably 35°C or lower, even more preferably 30°C or lower.

In steps 3 and 3', the microcrystalline wax (B) is preferably blended as a microcrystalline wax emulsion.
In addition, other components such as the above-mentioned color pigment (F), anti-sagging agent/anti-settling agent (G), antifoaming agent (H), dispersant/emulsifier (I), etc. are preferably added in step 3 or step 3'.

[Uses of aqueous antifouling composition, antifouling coating, and substrate with antifouling coating]
The present composition is preferably used to provide a coating formed from the composition on the surface of an article for the purpose of preventing fouling by aquatic organisms in water.
That is, the present composition is preferably used as an aqueous antifouling composition for fishing nets or an aqueous antifouling coating composition, and more preferably used as an aqueous antifouling composition for fishing nets.

The antifouling coating of this embodiment is an antifouling coating formed from the above-described present composition. The antifouling coating can be formed by applying the present composition to a substrate or by immersing the substrate in the present composition and then drying it. The antifouling coating film is preferably an antifouling coating used for the purpose of preventing the substrate from being fouled by aquatic organisms in water.
The antifouling coated substrate of this embodiment includes a substrate and the above-described antifouling coating provided on the surface of the substrate. The method for producing the antifouling coated substrate preferably includes a step of applying the composition to the substrate (application step) or a step of immersing the substrate in the composition (immersion step), and preferably further includes a step of drying the composition.

The composition can be applied by known methods such as brush coating, spray coating, and dip coating.
The thickness of the coating formed from the composition is set so that the final antifouling coating has a thickness as described below. The coating may be formed by one coat or by two or more coats (two or more coats).
The composition applied by the above-described method can be dried by leaving it at 23°C, for example, for preferably 0.5 to 14 days, more preferably 1 to 10 days, to form an antifouling coating.
The composition may be dried and cured under heating and/or air blowing.
When the antifouling coating is formed by coating, the thickness of the antifouling coating is not particularly limited, but is preferably at least 1 μm, more preferably at least 5 μm, even more preferably at least 10 μm, and is preferably at most 1000 μm, more preferably at most 500 μm, even more preferably at most 300 μm. When the antifouling coating has such a configuration, the antifouling coating has excellent long-term antifouling properties.

The immersion time in the immersion step is not particularly limited, but is, for example, preferably 1 minute or more, more preferably 5 minutes or more, and preferably 1 hour or less.
For example, when a fishing net is used as the substrate, the coating amount (%) is preferably 5% or more, more preferably 7% or more, even more preferably 10% or more, and is preferably 30% or less, more preferably 20% or less, even more preferably 15% or less.
The coating amount is measured by the method described in the examples.
Fishing nets coated with an antifouling coating made from this composition exhibit good antifouling properties over a long period of time even with a small amount of coating, and are able to prevent clogging of mesh holes due to the ability to prevent the attachment of aquatic organisms.

Furthermore, coatings formed from the present composition can be provided on various substrates, and can be used in a wide range of industrial fields, such as ships, fisheries, and underwater structures, to provide long-term antifouling properties to substrates.
Examples of substrates include ships (e.g., large steel ships such as container ships and tankers, hull shell plates for fishing boats, FRP boats, wooden boats, yachts, etc., including both newly built and repaired ships), underwater structures (e.g., oil pipelines, water conveyance piping, circulating water pipes, water supply and drainage outlets for factories and thermal and nuclear power plants, undersea cables, seawater utilization equipment (seawater pumps, etc.), megafloats, coastal roads, undersea tunnels, port facilities, various underwater civil engineering structures in canals and waterways, etc.), fishing materials (e.g., ropes, fishing gear, fishing nets, floats, buoys), diver suits, underwater goggles, oxygen cylinders, swimsuits, and torpedoes.
Among these, the substrate is preferably a fishing net.

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

[Production of aqueous antifouling composition]
<Components of aqueous antifouling agent composition>
The components used in the aqueous antifouling composition are shown in Table 1.

In the table, a1 to a3, b1 to b3, m1 to m3, n1, and n2 of A and A' represent the average number of moles added or the average number of repetitions per mole of silicone.
The solid content (%) in the table can be approximated to the amount of active ingredient in each component.

(Kinematic Viscosity of Polyether Silicone)
The kinematic viscosity is calculated using the following formula.
Kinematic viscosity (mm ² /s) = viscosity (cP) ÷ density (g/cm ³ )
The viscosity was measured at 23°C using a Brookfield viscometer in accordance with JIS K 7117-1:1999. The density was measured at 23°C using a specific gravity cup in accordance with JIS K 5600-2-4:1999.

(Calculation of the molar ratio [EO/PO] in polyether silicone (A))
The molar ratio [EO/PO] in polyether silicone (A) was calculated by ^{the following} formula based on the integral values of the methyl groups of PO at about 0.8 to 1.2 ppm and the non-methyl group portions of EO and PO at about 3 to 4 ppm in 1 H NMR.
EO/PO={([integral value of about 3-4 ppm]-[integral value of about 0.8-1.2 ppm])/4}/{[integral value of about 0.8-1.2 ppm]/3}
The measurement conditions for ¹ H NMR quantification are as follows.
Apparatus: AVANCE III 400 (manufactured by Bruker)
Measurement method: Single pulse method with a flip angle of 30 degrees Observed nucleus: ¹ H
Observation frequency: 400.1MHz
Lock solvent: deuterated chloroform Number of data points: 65536
Delay time: 1 s
Number of measurements: 64 Measurement temperature: room temperature Sample rotation speed: 20 Hz
The denatured site was identified as follows.
When ¹ H- ²⁹ Si HMBC showed a correlation of about 10 ppm in ²⁹ Si NMR, it was judged to be terminal modified, and when it showed a correlation of about -20 ppm, it was judged to be side chain modified (excluding the correlation of about 0 ppm in ¹ H NMR derived from dimethylsiloxane).
The measurement conditions for ²⁹ Si NMR quantification are as follows.
Apparatus: AVANCE III 400 (manufactured by Bruker)
Measurement method: Inverse gated decoupling method Observed nucleus: ²⁹ Si
Observation frequency: 79.49 MHz
Lock solvent: deuterated chloroform Number of data points: 32,768
Delay time: 90 seconds
Accumulation count: 512 Measurement temperature: room temperature Sample rotation speed: 20 Hz

<Preparation of aqueous antifouling composition>
(Examples 1 to 8, Comparative Examples 1, 2, and 4)
Polyether silicone (A), polybutene (C), and water-soluble organic solvent (E) were charged in the amounts shown in Table 2, and high-speed stirring was carried out for 5 minutes at a rotation speed of 2000 rpm using a high-speed stirrer (product name: High-Speed Stirring Homogenizer Homodisper 2.5 Type / manufactured by Primix Corporation). The amounts shown in Table 2 are the amounts blended as is; for example, in Example 1, 21.0 parts by mass of a microcrystalline wax emulsion with a solid content of 36% by mass was blended when the total composition was taken as 100 parts by mass.
Next, ion-exchanged water was added in the amount shown in Table 2, and the mixture was stirred for 10 minutes with the high-speed stirrer, to obtain an emulsion containing polyether silicone and polybutene.
To the resulting emulsion, the other components shown in Table 2 were added, and the mixture was stirred for 10 minutes using the high-speed stirrer to prepare a water-based antifouling composition.

Example 9
The polyether silicone (A) and the water-soluble organic solvent (E) were charged in the amounts shown in Table 2, and the mixture was stirred at high speed for 5 minutes at 2000 rpm using the high-speed stirrer.
Next, ion-exchanged water was added in the amount shown in Table 2, and the mixture was stirred for 10 minutes using the high-speed stirrer, yielding an emulsion containing polyether silicone.
To the resulting emulsion, the other components shown in Table 2 were added, and the mixture was stirred for 10 minutes using the high-speed stirrer to prepare a water-based antifouling composition.

(Comparative Example 3)
An emulsion was prepared with reference to Japanese Patent No. 4795013.
2 parts of polyether silicone, 3 parts of polybutene, and 0.2 parts of DKS-NL100 as a dispersant/emulsifier were charged, and 0.5 parts of distilled water was gradually added over 10 minutes while stirring at high speed at 2000 rpm using the high-speed stirrer.
Further, 4.3 parts of distilled water was added with high speed stirring to obtain a paste-like emulsion of polyether silicone and polybutene.
The other components were added to the resulting emulsion, and the mixture was stirred for 10 minutes using the high-speed stirrer to prepare a water-based antifouling composition.

[evaluation]
The resulting aqueous antifouling composition was evaluated as follows.
<Coating amount>
The mass (g)a of the aqueous antifouling composition on a test netting (polyethylene knotless netting (7 knots, 400 denier/50 strands)) before application and the mass (g)b after drying for 12 hours or more after application were measured, and the applied amount was calculated using the following formula.
Coating amount % = (ba)/a x 100

<Viscosity>
The viscosity of the aqueous antifouling agent composition was measured in accordance with ASTM D1200 by filling a Ford Cup No. 4 with a sample, allowing the sample to flow down through a hole in the bottom of the cup, and recording the time (seconds) for the sample to flow down as the viscosity of the sample.
More specifically, the hole in the bottom of the cup was first clamped, and the cup was filled with the sample, the temperature of which had been adjusted to 23°C to prevent bubbles from entering. Next, a glass plate was slid horizontally across the top edge of the cup to scrape off excess sample, and the glass plate was then placed on top of the cup. The hole in the bottom of the cup was then removed.
Next, the glass plate was removed by sliding it sideways, and at the same time the stopwatch was pressed. When the continuously flowing sample stopped, the stopwatch was stopped and the time taken for the sample to flow down was recorded.

<Storage stability>
The viscosity of the aqueous antifouling composition after storage at 40°C for 1 month was measured, and when the flow time was less than the initial viscosity plus 2 seconds, the storage stability was evaluated as good.
Furthermore, when the flow time was 2 seconds or more longer than the initial viscosity, or when it was impossible to measure, the storage stability was evaluated as poor. Here, the case where it was impossible to measure means when the flow time exceeded 40 seconds.

<Stain resistance>
A polyethylene knotless net (7 knots, 400 denier/50 strands) was immersed in each of the aqueous antifouling compositions prepared in the Examples and Comparative Examples at 23°C for 5 minutes, and then air-dried indoors for 48 hours to obtain a fishing net coated with an antifouling film.
This fishing net with an antifouling coating was immersed approximately 2 m below the sea surface in Hiroshima Bay, Hiroshima Prefecture. Every two months from the start of immersion, the ratio (%) of the area of the antifouling coating to which aquatic organisms had adhered (adhered area), relative to the total area of the antifouling coating of the fishing net, taken as 100%, was measured, and the static antifouling properties were evaluated based on the following evaluation criteria.
A: Adhesion area is less than 10% B: Adhesion area is 10% or more but less than 30% C: Adhesion area is 30% or more but less than 50% D: Adhesion area is 50% or more

From the results of the Examples and Comparative Examples, it is clear that the aqueous antifouling agent composition of the present invention has a low initial viscosity and exhibits good storage stability, and further exhibits good long-term antifouling properties even when the coating amount is small.
On the other hand, as shown in Comparative Examples 1 and 2, aqueous antifouling compositions using polyethersilicones having only ethyleneoxy groups or propyleneoxy groups were inferior in storage stability and also in long-term antifouling properties. Comparative Example 3, in which an emulsion of polyethersilicone (A) and polybutene (C) was prepared using a dispersant and an emulsifier without containing a water-soluble organic solvent (E), was also inferior in long-term antifouling properties. Furthermore, Comparative Example 4, which did not contain polyethersilicone (A), also had a high coating weight and was inferior in long-term antifouling properties.

Claims (13)

Polyether silicone (A),
Microcrystalline wax (B),
Polybutene (C),
An antifouling agent (D), and a water-soluble organic solvent (E),
The polyether silicone (A) is a polydimethylsiloxane in which at least one of a side chain and an end is modified with the following modifying group Y:
The water-soluble organic solvent (E) is at least one selected from the group consisting of isopropyl alcohol, methyl cellosolve, ethyl cellosolve, propyl cellosolve, and butyl cellosolve.
A water-based antifouling composition.

(R ^a represents a single bond or a divalent linking group, R ^b represents a hydrogen atom or a monovalent organic group having 1 to 15 carbon atoms, a and b represent integers of 1 or more, a/b is 0.1 to 2.0, and * represents the bonding position with Si.) 2. The aqueous antifouling composition according to claim 1, wherein the polyether silicone (A) is represented by the following formula (1):

(In formula (1), ^X1 and ^X2 each independently represent a hydrogen atom, an alkyl group having from 1 to 15 carbon atoms, or Y; ^X3 represents Y; R ^a represents a single bond or a divalent linking group; R ^b each represents a hydrogen atom or a monovalent organic group having from 1 to 15 carbon atoms; m, a, and b each represent an integer of 1 or greater; a/b is 0.1 to 2.0; n represents an integer of 0 or greater; and * represents the bonding position with Si. However, when n is 0, ^X1 and/or ^X2 is the above-mentioned Y.) 3. The aqueous antifouling agent composition according to claim 1, wherein the mass ratio of the microcrystalline wax (B) to the polyether silicone (A) [(B)/(A)] is 1.0 or more and 20.0 or less. 4. The aqueous antifouling composition according to claim 1 , wherein the microcrystalline wax (B) is blended as a microcrystalline wax emulsion. The aqueous antifouling composition according to any one of claims 1 to 4 , wherein the polyether silicone (A) is contained in an amount of 1 part by mass or more and 20 parts by mass or less per 100 parts by mass of the solid content of the aqueous antifouling composition. The aqueous antifouling composition according to any one of claims 1 to 5 , comprising 10 parts by mass or more and 35 parts by mass or less of the microcrystalline wax (B) per 100 parts by mass of the solid content of the aqueous antifouling composition. 7. The aqueous antifouling composition according to claim 1, wherein the antifouling agent (D) comprises at least one selected from the group consisting of cuprous oxide, copper pyrithione, and bisdimethyldithiocarbamoylzinc ethylenebisdithiocarbamate. 8. The aqueous antifouling composition according to claim 1, wherein the content of the one or more resins selected from the group consisting of acrylic resins and vinyl acetate resins is 3 parts by mass or less per 100 parts by mass of the solid content of the aqueous antifouling composition. The aqueous antifouling composition according to any one of claims 1 to 8 , which is for use in fishing nets. An antifouling coating formed from the aqueous antifouling composition according to any one of claims 1 to 9 . An antifouling coated substrate coated with the antifouling coating according to claim 10 . A method for producing the aqueous antifouling composition according to any one of claims 1 to 9, comprising the following steps 1 to 3 :
Step 1: A step of dissolving polyether silicone (A) and polybutene (C) in a water-soluble organic solvent (E) to obtain a solution. Step 2: A step of forcibly emulsifying the solution obtained in Step 1 in an aqueous medium to obtain an emulsion. Step 3: A step of mixing the emulsion obtained in Step 2 with a microcrystalline wax (B) and an antifouling agent (D). A method for producing the aqueous antifouling composition according to any one of claims 1 to 9 , comprising the following steps 1' to 3':
Step 1': A step of dissolving polyether silicone (A) in a water-soluble organic solvent (E) to obtain a solution. Step 2': A step of forcibly emulsifying the solution obtained in Step 1' in an aqueous medium to obtain an emulsion. Step 3': A step of mixing the emulsion obtained in Step 2' with microcrystalline wax (B), polybutene (C), and an antifouling agent (D).