JPH04264169A - Coating composition - Google Patents

Abstract

PURPOSE:To obtain a coating composition which has excellent storage stability and can give a coating film which is hydrolyzable and is homogeneously soluble in sea water when immersed in it by using a polymer of a specified monomer and/or a copolymer thereof with a vinyl monomer and an antifouling agent as essential components. CONSTITUTION:This composition essentially consists of at least one polymer of a monomer of the formula (wherein R1 to R3 are each alkyl or aryl, and at least one of them is branched alkyl; and R4 is alkyl or aryl) and/or a copolymer of at least one of the above monomers with at least one copolymerizable vinyl monomer (e.g. vinyl acetate) and an antifouling agent (e.g. cuprous oxide).

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating composition for preventing living things from adhering to the surface of underwater objects.

0002

[Prior Art] The surfaces of underwater objects, such as ship bottoms, buoys, fishing nets (aquaculture nets, fixed nets, etc.), underwater pollution prevention membranes, and various intake and drainage pipes for cooling, which are immersed in water, are covered with barnacles,
Various problems occur due to the adhesion of celluloids, mussels, algae, etc. In order to prevent contamination by these organisms,
It is well known that paints are applied to the surfaces of underwater objects to prevent organisms from adhering to them.

[0003] Early antifouling paints for preventing the adhesion of living organisms were designed to prevent marine organisms from adhering to the seawater because the resin that formed the coating did not dissolve in seawater, and only the antifouling agent dissolved in seawater. It was a type of paint that prevented the adhesion of This type of paint generally has a good initial antifouling effect, but the drawback is that the antifouling effect becomes insufficient over the long term.

The antifouling paints that have been put on the market as the above-mentioned improved type are so-called hydrolyzable self-polishing paints in which both the resin and the antifouling agent that form the paint film dissolve in seawater. Since the surface is eluted, an active antifouling coating surface is always maintained, making it easier to maintain the antifouling effect.

One of these hydrolyzable self-polishing paints is an antifouling paint using an organic tin copolymer. The antifouling effect of this type of paint is not fully satisfactory as both the antifouling agent and the resin component have an antifouling effect, but there is a limit to the wear of the paint film, or on the contrary, it wears out too much. The current situation is that no effect has been obtained. In addition, marine pollution caused by organic tin compounds has become a major social problem.

[0006] Therefore, as another type of hydrolyzable self-polishing paint, from the perspective of preventing marine pollution,
A coating material using an organosilicon (having an organosilyl group) polymer is disclosed in JP-A-63-215780 and is attracting attention.

[0007]

[Problems to be Solved by the Invention] However, paints using the above-mentioned organosilicon polymers have the following problems.

(a) Hydrolysis of the alkylsilyl groups contained in the polymer is very fast, and carboxyl groups are generated in the side chains of the polymer on the surface of the coating film, increasing hydrophilicity. is undesirable because the antifouling agent on the surface of the coating film is rapidly eluted and lost.

(b) The fact that the alkylsilyl group hydrolyzes too quickly as described in (a) above means that the resin itself lacks stability, and during the dispersion process during paint manufacturing, moisture in the atmosphere and pigment Also, the carboxyl groups generated when the resin itself is hydrolyzed by water contained in antifouling agents, etc., form complexes with pigments and metals such as cuprous oxide during paint storage, causing gelation of the resin. However, the storage stability of the paint was disadvantageous. To solve this problem, it has been proposed to use a water binder, but this is still insufficient to prevent gelation.

(c) After the coating film is immersed in the sea,
Hydrolysis of the alkylsilyl groups contained in the polymer is very rapid, but the polymer having carboxyl groups in the side chains forms a thick resin residue layer on the surface of the coating afterwards. The elution rate of this resin residue layer into the sea is slower than the elution rate of the antifouling agent, which prevents the antifouling agent deep in the coating film from leaching into the sea, resulting in a lack of antifouling effect.

[0011] In view of the problems (a) to (c) above, the present invention provides a paint that has good storage stability and dissolves uniformly in the sea at an appropriate rate when the paint film is immersed in the sea. To provide a coating composition that exhibits excellent antifouling performance over a long period of time without forming a resin residue layer that prevents the elution of an antifouling agent from deep within the coating film over time. The purpose is

0012

[Means for Solving the Problem] As a result of intensive research to achieve the above object, the present inventors have solved the above conventional problems by using a specific organosilicon polymer having a unique molecular structure. Knowing that all of (a) to (c) can be overcome, we have completed the present invention. That is, the present invention provides the following general formula (Chemical formula 2);

[0013]

[Case 2]

(However, in the formula, R1 to R3 are all groups selected from alkyl groups and aryl groups, and may be the same or different groups, but at least one is a branched alkyl group, and R4 is an alkyl group or an aryl group)

One or more polymers of the monomer A shown below, and/or one or two of the monomers A above.
A coating composition containing as essential components a copolymer of one or more vinyl monomers B that can be copolymerized with these and an antifouling agent. It is.

[0016]

Structure and operation of the invention The polymer used in the coating composition of the present invention is one or more polymers of monomer A represented by the above general formula (hereinafter referred to as polymer A). , or a copolymer of one or more of the above monomers A and one or more of the vinyl monomers B that can be copolymerized with these monomers (hereinafter referred to as copolymer AB). . Further, the above-mentioned polymer A and copolymer AB may be used together.

Monomer A has a triorganosilyl group [Si(R1)
(R2)(R3)] and an alkyl group or aryl group (
R4), and the unsaturated moiety in the molecule may be either cis (malate) type or trans (fumarate) type, or a mixture of both.

In the above triorganosilyl group, 3
The organic groups (R1), (R2), and (R3) are groups selected from alkyl groups and aryl groups, and may be the same group or different groups, At least one is isopropyl, isobutyl, s-butyl,
It is a branched alkyl group having 3 to 22 carbon atoms such as t-butyl. Other organic groups mentioned above include linear alkyl groups having 1 to 22 carbon atoms, cyclic alkyl groups having 3 to 22 carbon atoms, aryl groups, and substituted aryl groups. Examples of the substituted aryl groups include halogen, Examples include aryl groups substituted with alkyl groups, acyl groups, nitro groups, or amino groups having up to about 10 carbon atoms.

[0019] The above alkyl group or aryl group (R4) may include a linear or branched alkyl group having 1 to 22 carbon atoms, a cyclopropyl group, a cyclobutyl group,
3 or more carbon atoms such as cyclopentyl group and cyclohexyl group
22 cyclic alkyl groups, aryl groups, substituted aryl groups similar to those described above, and the like.

Synthesis examples of monomer A include, for example, a method in which triorganosilane is dehydrated and condensed with a maleic acid monoalkyl ester obtained by an esterification reaction of maleic anhydride and an alcohol, and a method in which triorganosilane is dehydrated and The alkyl ester and triorganochlorosilane are combined with a base (for example, triethylamine, imidazole, etc.)
There is a method of carrying out a dehydrochlorination reaction in the presence of. Further, a fumarate derivative corresponding to a malate derivative can be easily obtained by subjecting a malate derivative to a thermal isomerization reaction using an amine catalyst or the like.

[0021] Such a monomer A has a triorganosilyl group whose at least one of the three organic groups (R1), (R2), and (R3) is the branched alkyl group. The steric effect has the function of preventing moisture from approaching the ester bond, which is the point of hydrolysis, and slowing down the rate of hydrolysis, thereby optimizing the rate. As a result, the stability of the polymer is increased, the hydrophilicization of the polymer is delayed, and the initial rapid elution of the antifouling agent is prevented, while at the same time the formation of a thick resin residue layer is eliminated, and the coating surface is constantly activated. This makes it possible to maintain an excellent antifouling effect over a long period of time.

Examples of the vinyl monomer B which is a constituent component of the copolymer AB include vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, and vinyl benzoate, methyl methacrylate, ethyl methacrylate, and methacrylate. butyl acrylate, methacrylic esters such as 2-ethylhexyl methacrylate, 2-hydroxyethyl methacrylate, acrylic esters such as ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, maleic acid Maleic acid esters such as dimethyl acid and diethyl maleate,
Examples include fumarate esters such as dimethyl fumarate and diethyl fumarate, styrene, vinyltoluene, α-methylstyrene, crotonate esters, and itaconate esters.

[0023] Such vinyl monomer B acts as a modifying component to impart various performances to the antifouling coating film depending on the use and purpose, and also has higher properties than monomer A alone. It is also a convenient component for obtaining high molecular weight polymers. The amount of monomer B to be used is set within an appropriate range, taking into consideration the above-mentioned performance and the antifouling effect based on monomer A. Copolymer A
If the proportion of monomer A constituting B is at least 5% by weight, preferably at least 10% by weight, the antifouling effect of the coating film will be sufficiently exhibited, so monomer B should be used within the above range. The amount may be set appropriately.

Polymer A and copolymer AB are obtained by solution polymerization, bulk polymerization, or emulsification of monomer A or monomer B as described above in the presence of a vinyl polymerization initiator according to a conventional method. By polymerizing by various methods such as polymerization and suspension polymerization,
Obtainable. When using a polymer as a paint, it is convenient to dilute it with an organic solvent to obtain a polymer solution with an appropriate viscosity.For this purpose, it is recommended to use solution polymerization or bulk polymerization. desirable.

The viscosity of the polymer solution is 150 poise or less/
Conveniently, the solids content of the polymer solution is between 5 and 90% by weight, preferably between 15 and 85% by weight.
It is preferable to set the amount within a range of % by weight.

The weight average molecular weight of the polymer A and copolymer AB obtained by the above method is 1000 to 30000.
It is desirable that it be in the range of 0. If this molecular weight is less than 1,000, it is difficult to form a normal coating film, and if the molecular weight is less than 300,000, it is difficult to form a normal coating film.
If it exceeds 100%, the solid content of the paint during coating will be low, resulting in the problem that only a thin coating can be obtained with one coating, and several coatings will be required.

Examples of vinyl polymerization initiators include azo compounds such as azobisisobutyronitrile and triphenylmethylazobenzene, peroxides such as benzoyl peroxide, di-t-butyl peroxide, and t-butyl peroxybenzoate. Oxides can be used.

Examples of organic solvents include xylene,
Aromatic hydrocarbon solvents such as toluene, aliphatic hydrocarbon solvents such as hexane and heptane, ester solvents such as ethyl acetate and butyl acetate, isopropyl alcohol,
Alcohol solvents such as butyl alcohol, ether solvents such as dioxane and diethyl ether, and ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone can be used, and these solvents may be used alone or as a mixture of two or more thereof.

In the coating composition of the present invention, the antifouling agent used as one of the essential components together with the above-mentioned polymer includes a wide variety of conventionally known antifouling agents. Broadly speaking, there are inorganic compounds, organic compounds containing metals, and organic compounds not containing metals.

Examples of inorganic compounds include copper compounds such as cuprous oxide, copper powder, copper thiocyanate, copper carbonate, copper chloride, and copper sulfate, zinc sulfate, zinc oxide, nickel sulfate, and copper-nickel alloys.

Examples of organic compounds containing metals include organotin compounds, organocopper compounds, organic nickel compounds, and organozinc compounds, as well as maneb, manseb, propineb, and the like.

Among organic compounds containing metals, organotin compounds include triphenyltin halides such as triphenyltin chloride and triphenyltin fluoride, tricyclohexyltin halides such as tricyclohexyltin chloride and tricyclohexyltin fluoride, and tributyltin chloride. , tributyltin halide such as tributyltin fluoride, triphenyltin hydroxide, tricyclohexyltin hydroxide, bis(triphenyltin)-
α・α-dibromosuccinate, bis(tricyclohexyltin)-α・α-dibromosuccinate, bis(tributyltin)-α・α-dibromosuccinate, bis(
triphenyltin) oxide, bis-(tricyclohexyltin) oxide, bis-(tributyltin) oxide, triphenyltin acetate, tricyclohexyltin acetate, tributyltin acetate, triphenyltin monochloroacetate, triphenyltin versatuccinic acid ester, triphenyltin dimethyldithio These include carbamates and triphenyltin nicotinic acid esters.

In addition, examples of organic copper compounds include copper oxine, copper nonylphenolsulfonate, copper bis(ethylenediamine)-bis(dodecylbenzenesulfonate), copper acetate, copper naphthenate, copper bis(pentachlorophenolic acid), etc. be.

Furthermore, as organic nickel compounds,
Examples of organic zinc compounds include nickel acetate and nickel dimethyldithiocarbamate, and zinc acetate, zinc carbazate, zinc dimethyldithiocarbamate, zinc pyrithione, and zinc ethylenebisdithiocarbamate.

Metal-free organic compounds include N-trihalomethylthiophthalimide, dithiocarbamic acid, N
Examples include -arylmaleimide, 3-substituted amino-1,3-thiazolidine-2,4-dione, and dithiocyano compounds.

Among metal-free organic compounds, examples of N-trihalomethylthiophthalimide include N-trichloromethylthiophthalimide and N-fluorodichloromethylthiophthalimide, and examples of dithiocarbamic acid include bis(dimethylthiocarbamoyl) disulfide,
Examples of N-arylmaleimide include ammonium N-methyldithiocarbamate, ammonium ethylenebis(dithiocarbamate), and milneb.
・6-Trichlorophenyl)maleimide, N-4-tolylmaleimide, N-3-chlorophenylmaleimide, N
-(4-n-butylphenyl)maleimide, N-(anilinophenyl)maleimide, N-(2,3-xylyl)
Examples include maleimide and the like.

Further, as the 3-substituted amino-1,3-thiazolidine-2,4-dione, 3-benzylideneamino-1,3-thiazolidine-2,4-dione, 3-(4
-methylbenzylideneamino)-1,3-thiazolidine-2,4-dione, 3-(2-hydroxybenzylideneamino)-1,3-thiazolidine-2,4-dione, 3
-(4-dimethylaminobenzylideneamino)-1・3
-Thiazoline-2,4-dione, 3-(2,4-dichlorobenzylideneamino)-1,3-thiazolidine-2.
Examples include 4-dione.

Examples of dithiocyano compounds include dithiocyanomethane, dithiocyanoethane, 2,5-dithiocyanothiophene, etc.; examples of triazine compounds include 2.
-Methylthio-4-t-butylamino-6-cyclopropylamino-s-triazine, etc., and 2.4
・5,6-tetrachloroisophthalonitrile, N・N-
Dimethyldichlorophenylurea, 4,5-dichloro-2
-N-octyl-3-(2H)isothiazolone, N・N
-dimethyl-N'-phenyl-(N-fluorodichloromethylthio)sulfamide, tetramethylthiuram disulfide, 3-iodo-2-propynylbutyl carbamate, 2-(methoxycarbonylamino)benzimidazole, and the like.

In the present invention, one or more antifouling agents are selected from among the various antifouling agents mentioned above.
The amount used is that the proportion of antifouling agent in the paint formulation is 0.1 to 8.
Preferably, it is 0% by weight. If the antifouling agent is less than 0.1% by weight, no antifouling effect can be expected, and if it exceeds 80% by weight, defects such as cracks and peeling will easily occur in the formed coating film, and effective antifouling properties will not be achieved. It becomes difficult to get caught.

The coating composition of the present invention thus constituted may contain pigments such as Bengara, titanium dioxide, and talc, colorants such as dyes, water binders, and sauces commonly used in coatings. Can contain stopper, anti-color separation agent, anti-settling agent, anti-foaming agent, etc.

Examples of water binding agents include trialkyl orthoformates such as trimethyl orthoformate, triethyl orthoformate, and tributyl orthoformate; trialkyl orthoacetates such as trimethyl orthoacetate, triethyl orthoacetate, and tributyl orthoacetate; trimethyl borate,
Trialkyl orthoborates such as triethyl orthoborate and tributyl orthoborate, tetramethyl silicate, tetraethyl silicate, tetrabutyl silicate, tetra(2-methoxyethyl)silicate, tetra(
Tetra (substituted) alkyl silicates such as 2-chloroethyl) silicate, tetra (substituted) aryl silicates such as tetraphenyl silicate, tetrabenzyl silicate, tetra (substituted) alkyl silicates or tetra (substituted) aryl silicates condensates (dimers, trimers, tetramers, fuxamers, etc.)
Examples thereof include hydrolyzable ester compounds such as, and compounds having isocyanate groups such as phenyl isocyanate and benzenesulfonyl isocyanate.

[0042] In order to form an antifouling coating film on the surface of an object to be immersed in seawater using the coating composition of the present invention, it is applied to the surface of the object by an appropriate means, and then the coating composition is applied at room temperature or under heating. A dry coating film can be easily formed by removing the solvent by volatilization.

[0043]

Effects of the Invention The coating composition of the present invention has good stability during the dispersion process during coating production and during storage, and when the coating film is immersed in the ocean, it is immersed in the ocean at an appropriate speed and uniformly. In addition, there is little concern that a resin residue layer will form over time, which prevents the elution of the antifouling agent from deep within the coating film. Therefore, by using it for the bottom of ships, underwater structures such as fishing nets and cooling water pipes that need to prevent biological fouling in the sea, and even sludge diffusion prevention membranes for marine civil engineering works, it can prevent biological fouling on the surfaces of these objects. Excellent antifouling effects can be maintained over a long period of time.

[0044]

[Examples] Next, the present invention will be specifically explained using production examples, working examples, and comparative examples. Parts and percentages in the examples are by weight. The molecular weight represents the weight average molecular weight determined by GPC. In addition, monomer A (A1 to A7 used in the following production examples)
) is the monomer shown in the general formula above, and the groups R1 to R3 and R4 in the general formula have the structures as shown in Table 1 below, and () in the table The number indicates the number of groups.

[0045]

[Table 1]

Production Examples 1 to 5 Solvent a was charged into a flask equipped with a stirrer according to the formulation shown in Table 2 below, the temperature was raised to a predetermined reaction temperature, and monomer A and monomer B were added while stirring. A mixed solution of polymerization catalyst a and polymerization catalyst a was dropped into the flask over a period of 3 hours, and after the dropwise addition was completed, the mixture was maintained at the same temperature for 30 minutes. Then, a mixture of solvent b and polymerization catalyst b was added dropwise over 20 minutes, and stirring was continued for 2 hours at the same temperature to complete the polymerization reaction. Finally, a dilution solvent was added for dilution to obtain each polymer solution S1 to S5.

[0047]

[Table 2]

Production Example 6 In a heat-resistant and pressure-resistant container, monomer A1,
A6, monomer B, and polymerization catalyst a were charged, and the container was completely sealed and heated to a predetermined reaction temperature while shaking, and the reaction was further continued at the same temperature for 8 hours to complete the reaction. next,
Add diluting solvent and dissolve by shaking for 1 hour to obtain polymer solution S.
I got 6.

Production Example 7 In a flask equipped with a stirrer, solvent a,
Monomer A7, monomer B, and polymerization catalyst a were charged, heated to a predetermined reaction temperature while stirring, continued stirring at the same temperature for 6 hours, and diluted with a diluting solvent to obtain polymer solution S7. .

[0050]

[Table 3]

Comparative Production Example 1 Produced in the same manner as in Example 1, except that 40 parts of methyl methacrylate, 20 parts of octyl acrylate, and 40 parts of tributyltin methacrylate were used instead of monomer A1 and vinyl acetate. An organic tin copolymer solution T8 was obtained. The obtained copolymer has a molecular weight of 90,000 and is a 50% xylene solution.

Comparative Production Example 2 Except that 35 parts of methyl-(trimethylsilyl)malate and 65 parts of Beoba 9 (trade name of vinyl ester manufactured by Ciel) were used in place of monomer A1 and vinyl acetate.
An organic silicon copolymer solution S9 was obtained in the same manner as in Example 1. The molecular weight of the obtained copolymer was 15,000, 50%
It is a xylene solution.

Comparative Production Example 3 In place of monomer A1 and vinyl acetate, 35 parts of methyl-(tri-n-hexylsilyl)malate, Beoba 9 (
An organosilicon copolymer solution S10 was obtained in the same manner as in Example 1, except that 65 parts of vinyl ester (trade name, manufactured by Ciel) was used. The molecular weight of the obtained copolymer was 13,000
This is a 50% xylene solution.

[0054] The polymer solutions S1 to S7 prepared in Examples 1 to 7 and Comparative Examples 1 to 3 were used as they were in Example 1.
Polymer solution T8 prepared in comparative production example as sample ~7
, S9 and S10 as samples of Comparative Examples 1 to 3, respectively.
It was subjected to the following resin solubility test.

<Resin solubility test> Each sample was coated on one side of a glass plate (30 mm x 50 mm x 1 mm) degreased with acetone so that the dry film thickness was 200 μm, and heated in a desiccator at 20° C. under 10 mmHg. Each test piece was prepared by drying for 16 hours. After each test piece was immersed in sterile filtered seawater for a predetermined period of time, it was immersed in distilled water for about 10 seconds to remove salt and then dried. From the difference in dry weight of each test piece before and after immersion in seawater, the difference in dry weight of each test piece before and after immersion in seawater was determined. The rate of resin dissolution into seawater was determined. Dissolution rate is 10-70μg/c
The range of m2/day was considered acceptable. The results are shown in Table 4.

[0056]

[Table 4]

Examples 8 to 14 Seven types of coating compositions were prepared by mixing and dispersing 100 parts each of polymer solutions S1 to S7 and 50 parts of cuprous oxide using a homomixer at 2000 rpm.

Comparative Examples 4 to 6 Three types of coating compositions were prepared in the same manner as Examples 8 to 14, except that T8, S9, and S10 were used as the polymer solutions.

Examples 8 to 14 and Comparative Examples 4 to 6 above
The following storage stability test was conducted using each coating composition.

<Storage stability test> Each coating composition was
200 cc was poured into a 50 cc mayonnaise bottle and sealed. Store this in a constant temperature and humidity chamber at 25°C and 75% RH.
After 2 weeks, 1, 3, and 6 months, each coating composition was examined for gelation. The case where gelation was not observed was judged as x, and the case where gelation was observed was judged as x. The results are shown in Table 5 below.

[0061]

[Table 5]

Examples 15-34 and Comparative Examples 7-9 Table 6
~ Prepare each component according to the formulation shown in Table 11, and
23 types of coating compositions were prepared by mixing and dispersing with a homomixer at 000 rpm. In addition, among the ingredients, Days Baron A630-20X [trade name manufactured by Kusumoto Kasei Co., Ltd.] is
It is an additive for preventing sagging.

[0063]

[Table 6]

[0064]

[Table 7]

[0065]

[Table 8]

[0066]

[Table 9]

[0067]

[Table 10]

[0068]

[Table 11]

[0069] Above Examples 8 to 34 and Comparative Examples 4 to 9
For each coating composition, the following resin residue layer measurement test and antifouling performance test were conducted to evaluate the performance. These results are shown in Tables 12 to 14 below.

<Resin residue layer measurement test> On one side of a sandblasted steel plate (50 mm x 100 mm x 1 mm),
Tarvinyl-based anti-rust paint was applied in advance and dried, and each paint composition was applied to a dry film thickness of 240 μm after two coats.
Spray paint so that the temperature is 20℃ and the humidity is 75%.
A test piece was prepared by drying it for one week in a constant temperature and humidity room.

[0071] This test piece was suspended in sterilized filtered seawater and immersed for a predetermined period of time, then immersed in distilled water for about 10 seconds to remove salt, dried, and embedded in epoxy resin. Thereafter, it was cut and polished, and the cross section of the coating film was observed under a microscope to confirm the presence or absence of a resin residue layer. If there is no resin residue layer or if there is, the thickness of the layer is 5 μm or less, it is passed.

<Antifouling Performance Test> Tarvinyl-based antirust paint was applied on both sides of a sandblasted steel plate (50 mm x 100 mm x 1 mm) in advance and dried, and then each paint composition was applied to the dry film thickness. Spray coated on both sides to a thickness of 240μm with two coats on each side, temperature 20℃, humidity 75℃.
% in a constant temperature and humidity chamber for one week to prepare a test piece.

[0073] This test piece was immersed in seawater for 18 months at Aioi Bay, Aioi City, Hyogo Prefecture, and the percentage of area occupied by attached organisms on the test coating was measured over time.

[0074]

[Table 12]

[0075]

[Table 13]

[0076]

[Table 14]

In the results shown in Tables 4, 5, and 12 to 14 above, first, the organotin copolymer solution T8 of Comparative Example 1
The dissolution rate of the coating film was slow, and the coating films of the coating compositions of Comparative Examples 4 and 7 using this coating had unsatisfactory long-term antifouling effects.

Furthermore, since the organosilicon copolymers of Comparative Examples 2 and 3 do not have a branched alkyl group in any of R1 to R3 in the general formula, the resin formed from this copolymer solution It was observed that the coating film had an abnormally high dissolution rate in the sea and a high rate of hydrolysis. Therefore, the coating compositions of Comparative Examples 5 and 6 using these compositions had poor storage stability, and gelation occurred within two weeks. Moreover, in the coating compositions of Comparative Examples 5 and 6 and Comparative Examples 8 and 9 using these, the antifouling performance of the coating film decreased in a short period of time.

In contrast, the coating films of each of the polymers of Examples 1 to 7 were immersed in seawater for 7 days, 30 days, and 9 days.
Even after 0 days, it shows stable and appropriate solubility (Table 4). In addition, Examples 8 to 1 using these
The coating composition of No. 4 has good storage stability (
Table 5). Furthermore, the coating compositions of Examples 8 to 34 using these resins had no resin residue layer or were thin enough to have no practical effect (Tables 12 to 14), and in the staining performance test, the resin residue layer was was not observed at all even after 18 months (Tables 12-14).

As is clear from the above test results, the coating composition of the present invention has excellent storage stability, and the coating film has
Hydrolysis occurs at an appropriate rate only on surfaces in contact with seawater, followed by dissolution into the seawater. Furthermore, it is easy to understand that stable antifouling performance can be maintained over a long period of time, as water does not penetrate into the interior of the coating film and no resin residue layer is observed.

Claims (1)

[Claims] Claim 1: The following general formula (chemical formula 1); or different groups, at least one of which is a branched alkyl group, and R4 is an alkyl group or an aryl group). and/or a copolymer of one or more of the above monomers A and one or more of the vinyl monomers B that can be copolymerized therewith, and an antifouling agent. A paint composition characterized by containing as an ingredient.