CN111868184A - Copolymer for antifouling coating composition, antifouling coating composition comprising the same - Google Patents

Abstract

An object of the present invention is to provide an antifouling coating composition that provides good storage stability of the coating and that the obtained antifouling coating film does not cause abnormality (whitening, peeling, cracking, etc.) of the coating film for a long period of time in seawater ), continuous and stable film solubility and antifouling effect. According to the present invention, there is provided a copolymer for an antifouling paint composition, wherein the copolymer for an antifouling paint composition is a monomer (a) and a polymerizable unsaturated monounsaturated monomer other than the aforementioned monomer (a). obtained by the copolymerization of the mixture of the body (b), the above-mentioned monomer (a) is represented by the general formula (1), the above-mentioned monomer (b) contains 2-methoxyethyl methacrylate, the above-mentioned monomer (a) is The content occupies 5 to 45% by mass in the total mass of the above-mentioned monomer (a) and the above-mentioned monomer (b), and the content of the above-mentioned 2-methoxyethyl methacrylate is in the above-mentioned monomer (a) and the above-mentioned monomer. (b) occupies 55 to 95 mass % of the total mass.

Description

Copolymer for antifouling coating composition, antifouling coating composition comprising the same

【Technical field】

The present invention relates to a copolymer for an antifouling coating composition, and an antifouling coating composition comprising the copolymer.

【Background technique】

Aquatic fouling organisms such as barnacles, dragon worms, blue mussels, algae, sea squirts, enteromorpha, sea lettuce, and silt are attached to ships (especially the bottom part of ships), fishing nets, and fishing net accessories. Such problems as fishery equipment and underwater structures such as aqueducts of power plants can cause problems such as damage to the function and appearance of ships, etc. Especially for ships, the increase in resistance leads to a decrease in speed or an increase in fuel consumption, which increases losses.

For this reason, a triorganosilyl group-containing copolymer is now coated on the surface of ships (especially the bottom part of the ship), fishing equipment such as fishing nets, fishing net accessories, or underwater structures such as aqueducts of power generation stations. An antifouling coating film is formed by using an antifouling paint, and such a method of preventing damage is widely used.

The triorganosilyl ester part of the triorganosilyl-containing copolymer is hydrolyzed in seawater, and the copolymer gradually dissolves in the seawater to renew the surface of the coating film, thereby exerting an antifouling effect.

As triorganosilyl group-containing copolymers, triorganosilyl group-containing copolymers composed of branched alkyl or aryl groups such as triisopropylsilyl ester or t-butyldiphenylsilyl ester or the like have been proposed A triorganosilyl group-containing copolymer composed of a base ester monomer and (meth)acrylate alkoxyalkyl ester such as 2-methoxyethyl (meth)acrylate (Patent Documents 1 to 4).

However, since the storage stability of the antifouling paint using this triorganosilyl group-containing copolymer as a carrier is poor, it has been proposed to mix a dehydrating agent such as ethyl silicate or anhydrite with the paint (Patent Document 5). to 6), but it is not sufficient, and there is a problem that the storage stability deteriorates when the humidity at the time of coating production is high.

In addition, these triorganosilyl group-containing copolymers have problems in that the initial coating film is not sufficiently dissolved, and the coating film may whiten or fouling organisms may adhere during the outfitting period or the initial parking period.

【Existing technical documents】

【Patent Literature】

[Patent Document 1] Japanese Patent Laid-Open No. 7-102193

[Patent Document 2] Japanese Patent Laid-Open No. 2001-226440

[Patent Document 3] Japanese Patent Laid-Open No. 2005-82725

[Patent Document 4] Japanese Patent Application Publication No. 2016-062432

[Patent Document 5] Japanese Patent Laid-Open No. 7-18216

[Patent Document 6] Japanese Patent Laid-Open No. 9-48948

[Content of the invention]

【Problems to be Solved by Invention】

An object of the present invention is to provide an antifouling coating composition that provides good storage stability of the coating and that the obtained antifouling coating film does not cause abnormality (whitening, peeling, cracking, etc.) of the coating film for a long period of time in seawater ), continuous and stable film solubility and antifouling effect.

【Means to solve the problem】

According to the present invention, there is provided a copolymer for an antifouling paint composition, wherein the copolymer for an antifouling paint composition is a monomer (a) and a polymerizable unsaturated monounsaturated monomer other than the above monomer (a). obtained by copolymerizing a mixture of the monomer (b), the monomer (a) is represented by the general formula (1), the monomer (b) contains 2-methoxyethyl methacrylate, the monomer (a) is The content of the above-mentioned monomer (a) and the above-mentioned monomer (b) occupies 5 to 45% by mass, and the content of the above-mentioned 2-methoxyethyl methacrylate is in the above-mentioned monomer (a) and the above-mentioned monomer. (b) occupies 55 to 95 mass % of the total mass.

As a result of earnest research by the present inventors, they found a copolymer obtained by adding a specific amount of 2-methoxyethyl methacrylate to the monomer (b) to be copolymerized with the monomer (a) having a specific structure. (A) When used as a carrier, an antifouling coating composition can be obtained, which has very good storage stability of the coating even when it is produced under high humidity, and the coating film does not whiten or peel off in seawater for a long time. , cracking and other abnormal coating film, long-term continuous and stable coating film solubility and antifouling effect of antifouling coating composition.

【Detailed ways】

The present invention will be specifically described below.

1. Antifouling coating composition

The antifouling paint composition of the present invention contains the copolymer (A) for an antifouling paint composition, and an antifouling agent (B).

1-1. Copolymer (A) for antifouling paint composition

The copolymer (A) for antifouling paint compositions is a triorganosilyl group-containing copolymer obtained by copolymerizing a mixture of a monomer (a) and a monomer (b). The copolymer (A) contains monomer units derived from the monomers (a) to (b).

<Single (a)>

The monomer (a) is a triorganosilyl methacrylate monomer and is represented by the general formula (1).

【Change 1】

(In the formula, R ¹ is a methyl group, and R ² , R ³ , and R ⁴ are selected from the group consisting of branched alkyl and phenyl groups having 3 to 8 carbon atoms, which may be the same or different)

In the present invention, examples of the monomer (a) represented by the general formula (1) include triisopropylsilyl methacrylate, triisobutylsilyl methacrylate, and tri-sec-butylmethyl methacrylate. Silyl grease, triisoamyl silyl methacrylate, tris(2-ethylhexyl) silyl methacrylate, triphenylsilyl methacrylate, diisopropyl methacrylate Isobutylsilyl ester, Diisopropylisoamylsilyl methacrylate, Diisopropyl(2-ethylhexyl)silyl methacrylate, Diisopropylphenylmethyl methacrylate Silyl Ester, Diisopropyl Cyclohexyl Silyl Methacrylate, tert-Butyl Diisopropyl Silyl Methacrylate, tert-Butyl Diisobutyl Silyl Methacrylate, tert-Butyl Methacrylate Butyldiisoamylsilyl ester, tert-butyldiphenylsilyl methacrylate, etc., preferably tert-butyldiphenylsilyl methacrylate and triisopropylsilyl methacrylate base esters, particularly preferably triisopropylsilyl methacrylate. One or two or more of these monomers are used, respectively.

<Single (b)>

The monomer (b) is a polymerizable unsaturated monomer other than the monomer (a), and can be copolymerized with the monomer (a). In the present invention, the monomer (b) is required to contain 2-methoxyethyl methacrylate, and the monomer (b) contains a specific amount of 2-methoxyethyl methacrylate, thereby obtaining a coating composition The product has the following technical effects: the storage stability is very good, the coating film will not cause whitening, peeling, cracking and other abnormality of the coating film for a long time, and the solubility of the coating film and the antifouling effect are continuous and stable.

The monomer (b) may contain only 2-methoxyethyl methacrylate or monomers other than 2-methoxyethyl methacrylate. As a monomer other than 2-methoxyethyl methacrylate, the following monomers are mentioned, for example.

●Triisopropylsilyl acrylate, Triisobutylsilyl acrylate, Tri-sec-butylsilyl acrylate, Triisoamylsilyl acrylate, Tris(2-ethylhexyl)silyl acrylate, Triphenylsilyl acrylate, Diisopropyl isobutyl silyl acrylate, Diisopropyl isoamyl silyl acrylate, Diisopropyl (2-ethylhexyl) silyl acrylate, Diisopropylphenylsilyl acrylate, diisopropylcyclohexylsilyl acrylate, tert-butyl diisopropyl silyl acrylate, tert-butyl diisobutyl silyl acrylate, tert-butyl acrylate Triorganosilyl acrylates such as butyl diisoamyl silyl ester and tert-butyl diphenyl silyl acrylate.

Methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, (meth)acrylic acid 2 -Ethylhexyl, phenyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 4-hydroxy (meth)acrylate Butyl, 2-methoxyethyl acrylate, 2-methoxypropyl (meth)acrylate, 4-methoxybutyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate , (meth)acrylates such as polyethylene glycol methyl ether (meth)acrylate, dimethylaminoethyl (meth)acrylate, and diethylaminoethyl (meth)acrylate.

Tertiary zinc carbonate (meth)acrylate, tertiary magnesium carbonate (meth)acrylate, tertiary copper carbonate (meth)acrylate, zinc octoate (meth)acrylate, magnesium octoate (meth)acrylate, octanoic acid Copper (meth)acrylate, Zinc laurate (meth)acrylate, Magnesium laurate (meth)acrylate, Copper (meth)acrylate, Zinc stearate (meth)acrylate, Hard Metal (meth)acrylic acid side chains such as magnesium (meth)acrylate and copper (meth)acrylate, metal (meth)acrylate such as zinc (meth)acrylate and copper (meth)acrylate (meth)acrylate ) acrylates.

●With vinyl chloride, vinylidene chloride, acrylonitrile, methacrylonitrile, vinyl acetate, vinyl benzoate, ethylene butyric acid, butyl vinyl ether, lauryl vinyl ether, N-vinyl pyrrolidone Equal functional vinyl compounds.

●Aromatic compounds such as styrene, vinyltoluene, α-methylstyrene, etc.

●Dialkyl ester compounds of unsaturated dibasic acids such as dimethyl malate, dibutyl malate, and dimethyl fumarate.

One or two or more of monomers other than 2-methoxyethyl methacrylate that can be copolymerized are used, respectively, and (meth)acrylates are preferred, and methyl (meth)acrylate is particularly preferred.

The mass ratio of the content of 2-methoxyethyl methacrylate in the monomer (b) is preferably 0.75 to 0.95, more preferably 0.8 to 0.95, and specifically, for example, 0.75, 0.8, 0.85, 0.9, 0.95, It can also be within a range between any two numerical values exemplified here.

<Synthesis of Copolymer (A)>

The copolymer (A) used in the antifouling paint of the present invention can be obtained by copolymerizing a mixture of the monomer (a) and the monomer (b). The above-mentioned copolymerization is carried out, for example, in the presence of a polymerization initiator.

Content of the monomer (a) in the said mixture is 5-45 mass %, Preferably it is 10-40 mass %, More preferably, it is 15-35 mass %. When the content of the monomer (a) is 5 to 45 mass %, the coating stability of the obtained antifouling coating composition is very good, and the coating film does not cause abnormalities such as whitening, peeling, cracking, etc. in seawater for a long time, and can start from the initial stage Maintain stable film solubility and antifouling properties. Specifically, the content may be, for example, 5, 10, 15, 20, 25, 30, 35, 40, or 45 mass %, and may be within a range between any two numerical values exemplified here.

Content of 2-methoxyethyl methacrylate in the said mixture is 55-95 mass %, Preferably it is 60-90 mass %, More preferably, it is 60-85 mass %. When the content of 2-methoxyethyl methacrylate is 55 to 95% by mass, the coating film formed by the obtained antifouling coating composition has good coating film solubility and antifouling effect in seawater from the initial stage, and does not It can cause abnormal coating film such as whitening, peeling, and cracking, and can maintain stable coating film solubility and antifouling effect for a long time. Specifically, the content may be, for example, 55, 60, 65, 70, 75, 80, 85, 90, or 95% by mass, and may be within a range between any two numerical values exemplified here.

The total content of the monomer (a) and 2-methoxyethyl methacrylate is 60% by mass or more, preferably 70% by mass or more, more preferably 60% by mass or more in the total mass of the monomer (a) and the monomer (b) It is 80 mass % or more. Within the above range, coating film abnormalities such as whitening, peeling, and cracking are not caused, and the coating film solubility is stable for a long period of time, and an excellent antifouling effect is exhibited. Specifically, the content may be, for example, 60, 65, 70, 75, 80, 85, 90, 95, or 100 mass %, and may be within a range between any two numerical values exemplified here.

The weight average molecular weight of the copolymer of the present invention is preferably 5,000 to 300,000. This is because when the molecular weight is less than 5,000, the coating film of the antifouling paint becomes fragile, and peeling or cracking is likely to occur, and when the molecular weight exceeds 300,000, the viscosity of the copolymer solution increases and handling becomes difficult. Specifically, the Mw is, for example, 5,000, 10,000, 20,000, 30,000, 40,000, 50,000, 60,000, 70,000, 80,000, 90,000, 100,000, 200,000, and 300,000, and may be within a range between any two numerical values exemplified here.

As said polymerization initiator, 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis-2-methylbutyronitrile, 2,2'-azobisisobutyronitrile are mentioned, for example Azo compounds such as dimethyl acid; benzoyl peroxide, di-tert-butyl peroxide, tert-butyl peroxybenzoate, tert-butyl peroxyisopropyl carbonate, tert-butyl peroxide 2-ethyl Hydroxyhexanoate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate and other peroxides. These polymerization initiators can be used alone or in combination of two or more. As the above-mentioned polymerization initiator, 2,2'-azobisisobutyronitrile and 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate are particularly preferable.

The molecular weight of the triorganosilyl ester-containing copolymer can be adjusted by appropriately setting the amount of the polymerization initiator used.

As a polymerization method, solution polymerization, bulk polymerization, emulsion polymerization, suspension polymerization, etc. are mentioned, for example. Among them, solution polymerization is particularly preferable because the above-mentioned copolymer (A) can be obtained easily and accurately.

In the above-mentioned polymerization reaction, an organic solvent can be used as necessary. Examples of the organic solvent include aromatic hydrocarbon-based solvents such as xylene, ethylbenzene, and toluene. Aliphatic hydrocarbon solvents such as hexane and heptane. Ester solvents such as ethyl acetate, butyl acetate, isobutyl acetate, and methoxypropyl acetate. Alcohol-based solvents such as isopropanol and butanol. Ether-based solvents such as dioxane, diethyl ether, and dibutyl ether. Ketone-based solvents such as methyl ethyl ketone and methyl isobutyl ketone, etc. Among them, an aromatic hydrocarbon-based solvent is particularly preferable, and xylene is more preferable. These solvents can be used alone or in combination of two or more.

The reaction temperature of the polymerization reaction is usually 70 to 120°C, which can be appropriately set according to the type of the polymerization initiator and the like, but is preferably 70 to 100°C. The reaction time of the polymerization reaction may be appropriately set depending on the reaction temperature and the like, and is usually about 4 to 8 hours.

The polymerization reaction is preferably carried out in an inert gas atmosphere such as nitrogen and argon.

1-2. Antifouling reagent (B)

As an antifouling agent (B), an inorganic agent and an organic agent are mentioned, for example.

As an inorganic reagent, cuprous oxide, copper thiocyanate (common name: copper rhodamine), copper powder, etc. are mentioned, for example. Among them, cuprous oxide and rhodamine copper are particularly preferred, and from the viewpoint of long-term stability during storage, cuprous oxide is more preferably surface-treated with glycerin, sucrose, stearic acid, lauric acid, lysine, mineral oil, or the like .

Examples of organic reagents include 2-mercaptopyridine-N-copper oxide (common name: copper pyrithione), 2-mercaptopyridine-N-zinc oxide (common name: zinc pyrithione), ethylenebis Zinc dithiocarbamate (common name: Zinc Dysen), 4,5-dichloro-2-n-octyl-3-isothiazolone (common name: SEA-NINE211), 3,4-dichlorophenyl -N-N-dimethylurea (common name: diuron), 2-methylthio-4-tert-butylamino-6-cyclopropylamino-s-triazine (common name-Irgarol1051), 2-(p-chloro) Phenyl)-3-cyano-4-bromo-5-trifluoromethylpyrrole (common name: ECONEA28), (±)4-[1-(2,3-dimethylphenyl)ethyl]- 1H-imidazole (common name: medetomidine) and the like.

These antifouling agents may be used alone or in combination of two or more.

The content of the antifouling agent in the composition of the present invention is not particularly limited, but is usually 0.1 to 75% by mass, preferably 1 to 60% by mass, in the solid content of the composition of the present invention. When the content of the antifouling agent is less than 0.1 mass %, there is a possibility that a sufficient antifouling effect cannot be obtained. When the content of the antifouling agent exceeds 75% by mass, the formed coating film is fragile, and the adhesiveness to the object to be coated is also weak, and the function as an antifouling coating film cannot be exhibited.

1-3. Other additives

The resin for antifouling paint of the present invention can be further added with dissolution regulator, plasticizer, pigment, dye, defoamer, dehydrating agent, thixotropic agent and organic solvent as antifouling paint according to actual needs.

Examples of the dissolution regulator include rosin, rosin derivatives, naphthenic acid, cycloalkenyl carboxylic acid, bicycloalkenyl carboxylic acid, tertiary carbonic acid, trimethylisobutenylcyclohexene carboxylic acid, and their metal salts, Monocarboxylic acid and its salt or alicyclic hydrocarbon resin, etc. These can be used individually or in combination of 2 or more types.

As said rosin derivative, hydrogenated rosin, disproportionated rosin, maleated rosin, formylated rosin, polymerized rosin, etc. can be illustrated. As said alicyclic hydrocarbon resin, as a commercial item, Quinton 1500, 1525L, 1700 (brand name, the Nippon Zeon company make) etc. are mentioned, for example.

Examples of plasticizers include phosphates, phthalates, adipates, sebacates, epoxidized soybean oil, alkyl vinyl ether polymers, and polyalkylene diacrylates. Alcohols, tert-nonyl pentasulfide, petrolatum, polybutene, tris(2-ethylhexyl) trimellitate, silicone oil, liquid paraffin, chlorinated paraffin, etc. These can be used individually or in combination of 2 or more types.

Examples of the dehydrating agent include synthetic zeolite-based adsorbents, orthoesters, silicates such as tetramethoxysilane and tetraethoxysilane, isocyanates, carbodiimides, and carbodiimidazoles. . These can be used individually or in combination of 2 or more types.

2. Manufacturing method of antifouling coating composition

The antifouling paint composition of the present invention can be produced by mixing and dispersing, for example, a mixed solution containing the above-mentioned copolymer, an antifouling agent, other additives, and the like using a disperser.

As the above-mentioned mixed solution, various materials such as a copolymer and an antifouling agent are preferably dissolved or dispersed in a solvent.

As the above-mentioned disperser, for example, a disperser which can be used as a fine pulverizer can be preferably used. For example, a commercially available homogenizer, sand mill, bead mill and the like can be used. In addition, the above-mentioned mixed liquid may be mixed and dispersed using an apparatus in which glass beads for mixing and dispersing are put into a container equipped with a stirrer.

3. Antifouling treatment method, antifouling coating and coating

In the antifouling treatment method of the present invention, the antifouling coating composition is used to form an antifouling coating film on the surface of an object to be coated. According to the antifouling treatment method of the present invention, the antifouling coating film is gradually dissolved from the surface so that the surface of the coating film is constantly renewed, whereby the adhesion of aquatic fouling organisms can be prevented.

As a to-be-coated-film formation material, a ship (especially a ship bottom), a fishing implement, an underwater structure etc. are mentioned, for example.

The thickness of the antifouling coating film may be appropriately set according to the type of the object to be coated, the sailing speed of the ship, the seawater temperature, and the like. For example, when the object to be coated is the bottom of a ship, the thickness of the antifouling coating film is usually 50 to 700 μm, preferably 100 to 600 μm.

【Example】

Examples and the like are shown below to further clarify the characteristics of the present invention. However, the present invention is not limited to these Examples.

% in each Production Example, Reference Example, Example, and Comparative Example represents mass %.

The heating residual component is a value obtained by heating at 125° C. for 1 hour based on JIS K 5601-1-2 (ISO 3251).

The weight average molecular weight (Mw) is a value (polystyrene conversion value) obtained by GPC.

The conditions of GPC are as follows.

Device... HLC-8220GPC manufactured by Tosoh Corporation

Column... TSKgel SuperHZM-M (manufactured by Tosoh Corporation) 2

Flow...0.35mL/min

Detector...RI

Column thermostat temperature 40℃

Eluent...THF

In addition, the unit of the compounding quantity of each component in the table|surface is g.

<Production Example 1 (Production of Copolymer P-1)>

In a 2000ml flask equipped with a thermometer, a reflux condenser, a stirring device and a dropping funnel, 400g of xylene was added, stirred under a nitrogen atmosphere, the temperature was raised to 85±2°C, maintained at 85±2°C, and formazan was added dropwise over 1 hour. 175 g of triisopropylsilyl methacrylate, 300 g of 2-methoxyethyl methacrylate, 25 g of methyl methacrylate, 1,1,3,3-tetramethylbutylperoxy-2-ethyl A mixed solution of 5 g of hexanoic acid ester (PEROCTA O, manufactured by NOF Corporation). After the dropwise addition, 0.5 g of 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate was added three times per hour at 85±2° C. to complete the polymerization reaction, and then the temperature was raised to 110°C and kept there. After cooling for 30 minutes, 100 g of xylene was added and dissolved at 90° C. or lower to obtain a copolymer solution P-1. The heating residual component of P-1 was 49.7%, and the weight average molecular weight was 52,000.

<Production Examples 2 to 8, Reference Examples 1 to 12>

Using the organic solvents, monomers, and polymerization initiators shown in Tables 1 to 2, copolymerization was performed in the same manner as in Production Example 1 to obtain copolymer solutions P-2 to P-8 and comparative copolymer solutions H-1 to H -12. The heating residual component and weight average molecular weight of each obtained copolymer solution were measured. The results are shown in Tables 1 to 2.

【Table 1】

Table 1

【Table 2】

<Examples 1 to 12, Comparative Examples 1 to 12>

Using the copolymer solutions P-1 to P-8 obtained in Production Examples 1 to 8 and Reference Examples 1 to 12, and the copolymer solutions H-1 to H-12 of Comparative Example, the mixtures shown in Tables 3 to 4 were used to prepare Antifouling coating compositions.

(Preparation method of coating composition)

Two humidifiers were operated to keep the humidity above 90% in an airflow, and a small bench-top sand mill (using glass beads with a diameter of 1.5 to 2.5 mm) was used for mixing and dispersion for 1 hour to prepare Examples 1 to 12 and Comparative Examples. After the antifouling coating compositions of 1 to 12 were divided into two 100-ml tin cans, the paint of one tin can was used for various tests of coating films, and the paint of the other tin can was used for storage stability evaluation.

(Storage stability evaluation of paint)

After measuring the viscosity of the paint put into a tin can, it was sealed and stored in a thermostat at 45°C for 3 months, and then the viscosity of the paint was measured with a B-type viscometer.

The evaluation of the storage stability of a coating material was performed according to the following method.

◎: The viscosity change of the paint is less than 500mPa·s/25°C (hardly thickening)

○: The viscosity of the paint is changed to 500 to 5000 mPa·s/25°C (slightly thickened)

△: The viscosity of the paint is changed to 5000 mPa·s/25°C or more (largely thickened)

×: The viscosity changes to the point that it cannot be measured (gel or solid)

The results are shown in Table 3 and Table 4.

(Hardness measurement of coating film)

The coating film hardness of the paint was measured using a pendulum hardness tester.

Each coating sample was coated on a release plate (100×200×2 mm) so that the thickness after drying was about 100 μm, and after drying at 40°C for 1 day, the hardness of the coating film was measured by a pendulum hardness tester in a room at 25°C. Determination. Values are counts.

The results are shown in Table 3 and Table 4.

(rotation test)

A rotating drum with a diameter of 515mm and a height of 440mm is installed in the center of the sink, which can be rotated by a motor. In addition, a cooling device for keeping the temperature of the seawater constant and a pH automatic controller for keeping the pH of the seawater constant are installed.

Test panels were prepared in the following manner.

First, on a titanium plate (71 x 100 x 0.5 mm), an anti-rust coating (epoxy vinyl type A/C) was applied and dried so as to have a thickness of about 100 μm after drying, thereby forming an anti-rust coating film . Next, the coating compositions obtained in Examples 1 to 12 and Comparative Examples 1 to 12 were applied on the above-mentioned antirust coating films, respectively, so that the thickness after drying was about 300 μm. The obtained coating material was dried at 40° C. for 3 days, thereby producing a test panel having a dry coating film having a thickness of about 300 μm.

The produced test panel was fixed to the rotating drum of the rotating apparatus of the said apparatus so that it might contact seawater, and the rotating drum was rotated at the speed of 20 knots. During this period, the temperature of the seawater was kept at 25°C, the pH was kept at 8.0-8.2, and the seawater was replaced once a week.

●Measurement of the dissolved amount of the coating film

The residual film thickness of each test panel at the initial stage and every one month after the start of the test was measured with a shape measuring laser microscope VK-X100 manufactured by KEYENCE Co., Ltd., and the dissolved coating film thickness was calculated from the difference to obtain the Dissolved amount of coating film (μm/month).

The results are shown in Table 3 and Table 4.

●Observation of the surface state of the coating film

In the measurement of the residual film thickness after 6 months of the spin test, the surface of each coating film was observed with the naked eye and a microscope to evaluate the surface state of the coating film.

The evaluation of the surface state of the coating film was performed according to the following criteria.

◎: No abnormality at all

○: A few capillary cracks are observed

△: Capillary cracks are observed on the entire surface of the coating film

×: Coating film abnormalities such as cracks, bubbles, or peeling are observed

The results are shown in Table 3 and Table 4.

●Whitening observation of coating film

In the measurement of the residual film thickness after 6 months of the rotation test, the presence or absence of whitening on the surface of each coating film was visually evaluated.

Evaluation of the presence or absence of whitening of the coating film surface by the naked eye was performed according to the following criteria.

○: The color of the coating film surface hardly changes

△: When the color of the coating film surface is slightly whitened

×: When the color of the entire coating film is noticeably whitened

The results are shown in Table 3 and Table 4.

●Measurement of L value of coating film

The L value (brightness) was measured with the colorimeter about the coating film before the spin test and the residual coating film after the spin test for 6 months. As the colorimeter, Color Meter ZE6000 manufactured by Nippon Denshoku Kogyo Co., Ltd. was used. For the L value (luminance), a value specified in JISZ 8781-4 (calculation formula of the CIE method) is used. Since white is 100 and black is 0 in the L value (brightness), when the surface of the coating film is whitened, the coating film becomes brighter and the number of the L value increases.

(Anti-fouling test (static immersion test))

Each of the antifouling paints obtained in Examples 1 to 12 and Comparative Examples 1 to 12 was coated on both sides of a rigid polyvinyl chloride board (100×200×2mm) so that the thickness of the dry coating film was about 200 μm . This test panel was immersed at 1.5 m below the sea surface in Owase City, Mie Prefecture, and was observed for 12 months to evaluate the contamination of the test panel by attached organisms. The evaluation was performed by visually observing the state of the coating film surface, and judged according to the following criteria.

◎: There is no adhesion of fouling organisms such as shellfish and algae, and there is almost no sludge.

○: There is no adhesion of fouling organisms such as shellfish and algae, and the adhesion of sludge is thin (to the extent that the coated surface is visible), and can be removed by lightly wiping with a brush.

△: No fouling organisms such as shellfish and algae are attached, but the sludge is so thick that the coating surface cannot be seen clearly and cannot be removed even by strong wiping with a brush.

×: A grade in which fouling organisms such as shellfish and algae adhered. The results are shown in Tables 3 and 4.

【table 3】

table 3

【Table 4】

Table 4

The antifouling agents, pigments and other additives in Table 3 and Table 4 are as follows.

＜Anti-fouling reagent＞

Cuprous oxide (manufactured by Nisshin Chemco, NC-301 with an average particle size of 3 μm)

Copper pyrithione (manufactured by Arch Chemicals, Copper Omadine)

＜Pigment＞

Iron Dan (manufactured by Toda Pigment, TODA COLOR EP-13D)

Talc (Matsumura Sangyo, CROWNTALC 3S)

Zinc oxide (made by Zhengtong Chemical, two kinds of zinc oxide (brand name))

Titanium oxide (manufactured by Furukawa Machinery & Metals, FR-41)

＜Other additives＞

Tetraethoxysilane (manufactured by KISHIDA Chemicals, reagent grade)

Rosin zinc salt (50% xylene solution)

Chlorinated paraffin (manufactured by Tosoh Corporation, trade name "EMPARA A-40S")

DISPARLON A603-20X (Kusimoto Chemical Manufacturing, fatty acid amide thixotropic agent)

From Table 3 and Table 4, it can be seen that the coatings produced by the coating compositions of the present invention (Examples 1 to 12) have good storage stability, and the dissolved amount of the formed coating film in seawater is maintained at a high level. There was no adhesion of fouling organisms such as shellfish and algae, and almost no adhesion of sludge in the test. In addition, the state of the dry coating film after 6 months of the spin test was good without any abnormalities such as whitening, cracking, and peeling.

On the contrary, the paints produced using the paint compositions of Comparative Examples 1 to 6 or 10 to 12 had poor storage stability compared to the Examples, and the paint films formed using the paints were prone to whitening.

The coating materials produced using the coating compositions of Comparative Examples 7 to 9 had a low amount of dissolution in seawater, and the adhesion prevention of fouling organisms was insufficient.

Claims (3)

1. A copolymer for an antifouling coating composition, characterized in that the copolymer for an antifouling coating composition is a monomer (a) and a polymerizable unsaturated monomer other than the monomer (a) (b) obtained by the copolymerization of the mixture, The monomer (a) is represented by the general formula (1), The monomer (b) contains 2-methoxyethyl methacrylate, The content of the monomer (a) occupies 5 to 45 mass % in the total mass of the monomer (a) and the monomer (b), The content of the 2-methoxyethyl methacrylate occupies 55 to 95% by mass in the total mass of the monomer (a) and the monomer (b), 【Change 1】

In the formula, R ¹ is a methyl group, and R ² , R ³ and R ⁴ are selected from the group consisting of a branched alkyl group having 3 to 8 carbon atoms and a phenyl group, and they are the same or different. 2. The copolymer of claim 1, wherein The total content of the monomer (a) and 2-methoxyethyl methacrylate occupies 70% by mass or more in the total mass of the monomer (a) and the monomer (b). 3. An antifouling coating composition comprising a copolymer and an antifouling agent, The said copolymer is the copolymer for antifouling coating compositions of Claim 1 or Claim 2.