JPH08199095A - Coating composition - Google Patents

Abstract

PURPOSE: To obtain a coating compsn. capable of exhibiting an excellent antifouling performance over a long period by using a copolymer of a monomer mixture comprising a triorganosilylated monomer and a hemiacetal monomer, and an antifouling agent. CONSTITUTION: This compsn. comprises as the indispensable components a copolymer of a monomer mixture comprising (A) a monomer having a trioranosilyl group of formula I (wherein R<1> to R<3> are each alkyl or aryl; and X is acryloyloxy, methacryloyloxy, maleoyloxy, or fumaroyloxy), (B) a monomer having a hemiacetal group of formula II (wherein R<4> is alkyl; R<5> is alkyl or cycloalkyl; and Y is acryloyloxy, methacryloyloxy, maleyloxy, or fumaroyloxy), and, if necessary, (C) other vinyl monomer copolymerizable with the monomers (A) and (B); and an antifouling agent. This compsn. is useful for preventing attachment of life to the surface of an underwater object and capable of forming a coating film free from cracking and peeling and capable of exhibiting an excellent antifouling performance over a long period.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a coating composition for preventing organisms from adhering to the surface of objects in the sea.

[0002]

BACKGROUND OF THE INVENTION Barnacles, which are submerged in seawater, buoys, fishing nets (aquaculture nets, stationary nets, etc.), underwater pollution prevention films, various intake and drainage pipes for cooling, are barnacles,
Various obstacles occur due to the attachment of cellula, mussels, and algae. To prevent contamination by those organisms,
It is well known that paints are applied to the surface of underwater objects to prevent organisms from attaching.

As an antifouling paint for preventing the attachment of organisms, at the initial stage, the resin forming the basic skeleton of the coating film does not dissolve in seawater, and rosin which is a component of the resin component is used. At the same time as dissolution, an antifouling agent is extracted from a coating film and dissolved in seawater, so that a paint of a type that prevents adhesion of marine organisms has been used. This type of coating composition generally has a good antifouling effect in the initial stage because the resin component forming the basic skeleton remains, but has a drawback that the antifouling effect is insufficient for a long period of time.

As this improved type, a so-called hydrolyzable self-polishing type paint in which a resin having a basic skeleton forming a coating film is hydrolyzed by seawater has come to be used. This type of coating material has the advantage that the surface of the coating film is eluted, so that the active surface of the coating film for antifouling is always maintained, and the sustainability of the antifouling effect is easily obtained.

Organotin polymers have hitherto been widely used as such hydrolyzable self-polishing paints, but in recent years, marine pollution due to organotin compounds released as an antifouling agent after hydrolysis has been conducted. Is becoming a big social problem. Therefore, a hydrolysis-type antifouling paint containing no organic tin is strongly desired.

As a hydrolyzable self-polishing coating, Japanese Patent Publication No. 60-500452 discloses many examples of various hydrolyzable groups, among which organic silicon (alkoxysilyl group or organo group) is used. Polymers utilizing the hydrolyzability of (meth) acrylate having a silyl group are also shown. Further, JP-A-4-103671 also discloses a composition for an antifouling coating material, which uses a vinyl copolymer having a hemiacetate ester group or a hemiketal ester group as a hydrolysis group.

[0007]

However, the special table Sho 60
In JP-A-500452, although there is a description of production examples of tris (4-methyl-2-pentoxy) silyl acrylate in Examples, a description of a polymer composition using these monomers is given. Moreover, the test result as an antifouling paint is not shown. Further, regarding the organosilyl group, even though there is a description of SiR _{3 in} the claims, there is no description in the examples, and there is no description about which composition shows suitability as an antifouling paint. I can't.

The present inventors have investigated acrylic acid ester resins, methacrylic acid ester resins, maleic acid ester resins and fumaric acid ester resins having an organosilyl group in their side chains, and as a result, have found that they have an organosilyl group in their side chains. The rotary test, which is the most important as a hydrolysis-type antifouling paint, is a test of fixing the test piece to the outer surface of a cylindrical drum, and rotating the drum at a peripheral speed of 16 knots in seawater. ) Does not exhibit good solubility, does not exhibit good antifouling properties in an antifouling immersion test, does not show good adhesion to the substrate or undercoating due to cracking, and the coating film falls off when immersed in seawater. However, it was discovered that there are problems such as not being suitable as an antifouling paint.

Further, regarding the antifouling coating composition disclosed in JP-A-4-103671, an acrylic acid ester resin, a methacrylic acid ester resin, and maleic acid in which a hemiacetate ester group or a hemiketal ester group is introduced into a side chain are disclosed. As a result of studying acid ester resins and fumaric acid ester resins, vinyl polymers introduced with a necessary and sufficient amount of the above groups for imparting solubility in water for antifouling paints are hydrophilic by pushing them side by side. It was found that the coating film swells and wrinkles occur in seawater, and sufficient antifouling performance cannot be exhibited.

In view of the above circumstances, the present invention provides a hydrolyzable self-polishing coating composition which is free from cracking and peeling of the coating film, and which can be dissolved in the sea at an appropriate speed and uniformly. The present invention aims to provide a coating composition that exhibits excellent antifouling performance for a long period of time.

[0011]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies in order to achieve the above objects, and as a result, have found that a copolymer of an organosilyl group-containing monomer and a hemiacetate ester group-containing monomer is a copolymer. By using it, a stable coating wear rate can be obtained in the rotary test, good antifouling property can be exhibited for a long time, and since it does not cause cracking, it has good adhesion to the base material and undercoat paint. It was found that all the properties required for the hydrolyzable antifouling paint can be satisfied, and the present invention was completed.

That is, the present invention provides the following general formula (1): (However, in the formula, each of R ^{1 to} R ³ is a group selected from an alkyl group and an aryl group, and may be the same group or different groups. An acryloyloxy group, a methacryloyloxy group, a maleinoyloxy group or a fumaroyloxy group) and the following general formula (2); (In the formula, R ⁴ is an alkyl group, R ⁵ is an alkyl group or a cycloalkyl group, and Y is an acryloyloxy group, a methacryloyloxy group, a maleinoyloxy group or a fumaroyloxy group.) A copolymer of a monomer mixture containing a monomer B and, if necessary, another vinyl monomer C copolymerizable with the monomers A and B, and an antifouling agent as essential components. The present invention relates to a coating composition characterized by the above.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION In the coating composition of the present invention,
One or two of the monomer A represented by the above general formula (1)
1 or more and one of the monomers B represented by the above general formula (2)
A copolymer of a monomer mixture containing one or more kinds and optionally one or more kinds of other vinyl-based monomers C copolymerizable with these monomers A and B is essential. It was used as one of the ingredients.

The monomer A is, as represented by the general formula (1), an acryloyloxy group, a methacryloyloxy group, a maleinoyloxy group [mainly a monoalkyl ( It has a C1-6 ester maleinoyloxy group] or a fumaroyloxy group [mainly a monoalkyl (C1-6) fumaroyl ester ester] and a triorganosilyl group.

In the triorganosilyl group, the three alkyl groups or aryl groups (R ^{1 to} R ³ ) may be the same or different from each other. Specifically, a linear alkyl group having 20 or less carbon atoms such as methyl, ethyl, n-propyl, and n-butyl; a carbon number of 20 or less such as isopropyl, isobutyl, s-butyl, and t-butyl. Examples thereof include branched alkyl groups; cyclic alkyl groups such as cyclohexyl groups; aryl groups such as phenyl group, tolyl group, xylyl group, biphenyl group, and naphthyl group; and substituted aryl groups thereof. Replacement ant
The aryl group is an aryl group substituted with a halogen, an alkyl group having up to about 18 carbon atoms, an acyl group, a nitro group or an amino group.

Examples of the monomer A having a (meth) acryloyloxy group in the molecule include trimethylsilyl (meth) acrylate, triethylsilyl (meth) acrylate and tri-n-propylsilyl. (Meth) acrylate, tri-n-butylsilyl (meth) acrylate, tri-n-amylsilyl (meth) acrylate, tri-n-hexylsilyl (meth) acrylate, tri-n-octylsilyl (Meth) acrylic
Tri-n-dodecylsilyl (meth) acrylate,
Triphenylsilyl (meth) acrylate, tri-p-
Methylphenylsilyl (meth) acrylate, tribenzylsilyl (meth) acrylate, triisopropylsilyl (meth) acrylate, triisobutylsilyl (meth) acrylate, tri-s-butylsilyl (meth) acrylate -, Tri-2-methylisopropylsilyl (meth) acrylate, tri-t-butylsilyl (meth) acrylate and the like.

Other examples having a (meth) acryloyloxy group in the molecule include ethyldimethylsilyl (meth) acrylate and n-butyldimethylsilyl (meth).
Acrylate, diisopropyl-n-butylsilyl (meth) acrylate, n-octyldi-n-butylsilyl (meth) acrylate, diisopropylstearylsilyl (meth) acrylate, dicyclohexylphenylsilyl (meth) acrylate , T-butyldiphenylsilyl (meth) acrylate, lauryldiphenylsilyl (meth) acrylate, and the like.

Further, as having a maleinoyloxy group or a fumaroyloxy group in the molecule, triisopropylsilylmethyl maleate, triisopropylsilylamyl maleate, tri-n-butylsilyl-n-butyl maleate, t- Butyldiphenylsilylmethyl male
, T-butyldiphenylsilyl-n-butylmale
, Triisopropylsilylmethyl fumarate, triisopropylsilyl amyl fumarate, tri-n-butylsilyl-n-butyl fumarate, t-butyldiphenylsilylmethyl fumarate, t-butyldiphenylsilyl -N-butyl fumarate and the like can be mentioned.

The monomer B has, as represented by the general formula (2), an acryloyloxy group similar to the unsaturated group (X) of the monomer A as an unsaturated group (Y) in the molecule. Group, methacryloyloxy group, maleinoyloxy group [mainly monoalkyl (C1-6) ester maleinoyloxy group] or fumaroyloxy group [mainly monoalkyl (C1-6) ester fumaroyloxy group] In addition to having, it also has a hemiacetal group.

In the hemiacetal group, R ⁴ is a linear or branched alkyl group having 12 or less carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl and t-butyl. R ⁵ is a linear or branched alkyl group having 12 or less carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, cyclohexyl or substituted cyclohexyl, etc. Is a cycloalkyl group.

Examples of the monomer B include acrylic acid, methacrylic acid, maleic acid (or maleic acid monoester), fumaric acid (or fumaric acid monoester).
A carboxyl group-containing vinyl monomer consisting of, and an alkyl vinyl ether such as ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, hexyl vinyl ether, 2-ethylhexyl vinyl ether,
It is obtained by an addition reaction with cycloalkyl vinyl ethers such as cyclohexyl vinyl ether and the like by a conventional method.

Other vinyl monomers C copolymerizable with these monomers A and B include acrylic acid ester, methacrylic acid ester, styrene, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl benzoate and the like. , Vinyltoluene, α-methylstyrene, crotonic acid esters, itaconic acid esters, fumaric acid esters, and the like.

In the monomer mixture, the proportions of the monomers A and B and the other vinyl-based monomer C copolymerizable therewith can be appropriately set according to the purpose of use of the coating composition, but in general, The amount of the monomer A is 1 to 80% by weight, the amount of the monomer B is 1 to 80% by weight, and the amount of the other vinylic monomer C copolymerizable with them is 0 to 98% by weight. Is good.

The copolymer used as an essential component in the present invention is obtained by subjecting such a monomer mixture to solution polymerization, bulk polymerization, emulsion polymerization, suspension polymerization in the presence of a vinyl polymerization initiator according to a conventional method. It can be obtained by polymerizing by various methods such as. When this copolymer is used for paints, it is generally convenient to dilute it with an organic solvent to obtain a polymer solution having an appropriate viscosity. For that purpose, a solution polymerization method or a bulk polymerization method is used. It is desirable to adopt.

As the vinyl polymerization initiator, azo compounds such as azobisisobutyronitrile and triphenylmethylazobenzene, benzoyl peroxide, di-t-butyl peroxide, t-butyl peroxybenzoate,
Peroxides such as t-butyl peroxyisopropyl carbonate are used.

Examples of the organic solvent include aromatic hydrocarbon solvents such as xylene and toluene, aliphatic hydrocarbon solvents such as hexane and heptane, ester solvents such as ethyl acetate and butyl acetate, isopropyl alcohol and butyl alcohol. Alcohol solvent such as alcohol, dioxane, ether solvent such as diethyl ether, methyl ethyl ketone,
A ketone solvent such as methyl isobutyl ketone may be used, and one or more of these solvents may be used.

The copolymer obtained by such a method preferably has a weight average molecular weight of 1,000 to 150,000. If the molecular weight is too low, it will be difficult to form a normal coating film, and if it is too high, the coating solid content will be too low to obtain a thin coating film with one coating, which requires more coating times. Comes out. The viscosity of the polymer solution composed of this copolymer is 25 ° C.
Is preferably 150 poise or less, for which the solids content of the polymer solution should range from 5 to 90% by weight, preferably from 15 to 85% by weight.

In the coating composition of the present invention, conventionally known antifouling agents are widely included as the other antifouling agent. Broadly classified, there are inorganic compounds, organic compounds containing metals, and organic compounds containing no metals.

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

Examples of the organic compound containing a metal include organic copper compounds, organic nickel compounds and organic zinc compounds, and manneb, manceb, propineb and the like can also be used. Organic copper compounds include oxine copper, copper nonylphenol sulfonate, and cupper bis (ethylenediamine) -bis (dodecylbenzene sulfonate).
G), copper acetate, copper naphthenate, copper bis (pentachlorophenolate), etc. are organic nickel compounds.
Nickel acetate, nickel dimethyldithiocarbamate, etc., and organic zinc compounds include zinc acetate, zinc carbamate, zinc dimethyldithiocarbamate, zinc pyrithione, zinc ethylenebisdithiocarbamate, etc., respectively.

As the organic compound containing no metal, N-
Trihalomethylthiophthalimide, dithiocarbamic acid, N-arylmaleimide, 3-substituted amino-1,3
-Thiazolidine-2,4-diones, dithiocyano compounds, triazine compounds and others.

Examples of N-trihalomethylthiophthalimide include N-trichloromethylthiophthalimide and N-fluorodichloromethylthiophthalimide, and examples of dithiocarbamic acid include bis (dimethylthiocarbamoyl) disulfide, ammonium N-methyldithiocarbamate, ethylenebis (dithiocarbamine). Acid) ammonium, milneb and the like, respectively.

As the N-arylmaleimide, N-
(2,4,6-Trichlorophenyl) maleimide, N-
4-tolylmaleimide, N-3-chlorophenylmaleimide, N- (4-n-butylphenyl) maleimide, N
Examples thereof include-(anilinophenyl) maleimide and N- (2,3-xylyl) maleimide.

3-Substituted amino-1,3-thiazolidine-
As 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-2,4
-Zeon and the like.

Examples of dithiocyano compounds include dithiocyanomethane, dithiocyanoethane, and 2,5-dithiocyanothiophene, and examples of triazine compounds include 2 compounds.
-Methylthio-4-t-butylamino-6-cyclopropylamino-s-triazine and the like, respectively.

Other organic compounds containing no metal include 2,4,5,6-tetrachloroisophthalonitrile, N, N-dimethyldichlorophenylurea and 4,5-
Dichloro-2-N-octyl-3- (2H) isothiazolone, N, N-dimethyl-N'-phenyl- (N-fluorodichloromethylthio) sulfamide, tetramethylthiuram disulfide, 3-iodo-2- Propynyl butyl carbamate, 2- (methoxycarbonylamino)
Benzimidazole, 2,3,5,6-tetrachloro-
4- (methylsulfonyl) pyridine, diiodomethylparatolylsulfone, bisdimethyldithiocarbamoyl zinc ethylene bisdithiocarbamate, phenyl (bispyridine) bismuth dichloride, 2- (4-thiazolyl) benzimidazole, trif Examples include enylboron pyridine and the like.

In the present invention, one or more kinds of antifouling agents are selected and used from the various antifouling agents as described above. 80
It is good to set it as a weight percent, preferably 1 to 60 weight percent. If the amount of the antifouling agent is too small, the antifouling effect cannot be expected, and if the amount of the antifouling agent is too large, defects such as cracks and peeling are likely to occur in the formed coating film, making it difficult to obtain effective antifouling properties.

The coating composition of the present invention having the above-mentioned structure includes coloring agents such as pigments and dyes such as stalks, titanium dioxide, talc and zinc oxide, water binders, and anti-sagging agents commonly used in paints. Agents, color separation preventing agents, anti-settling agents, antifoaming agents and the like can be added.

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 at room temperature or under heating. It is only necessary to volatilize and remove the solvent underneath, and a dry coating film having excellent antifouling performance can be easily formed on the surface of the object by this method.

[0040]

EXAMPLES Next, the present invention will be described with reference to Reference Examples (Synthesis Examples of Monomer B that is a Hemiacetate Ester-Containing Monomer), Copolymer Production Examples, Examples and Comparative Examples. This will be specifically described. Parts in each example are parts by weight, viscosity is the measured value of foam viscosity at 25 ° C., and molecular weight is the polystyrene-converted weight average molecular weight by GPC.

Reference Examples 1 to 3 In a flask equipped with a stirrer, according to the composition shown in Table 1,
First, as raw material 1, EVE (ethyl vinyl ether),
PrVE (Pyropyrvinyl ether) or CHVE
(Cyclohexyl vinyl ether) was charged, and the temperature was raised to 60 ° C. while stirring and introducing nitrogen gas. Next,
AA (acrylic acid) as a raw material 2 was added dropwise thereto for 1 hour, and the reaction was completed by maintaining the temperature for 24 hours after the completion of the addition. In this way, three types of hemiacetate ester group-containing monomers with the abbreviations shown in Table 1, that is, the monomer B were synthesized.

[0042]

Reference Examples 4 to 6 PrVE (pyropyrvinyl ether) was used as the raw material 1.
MAA (methacrylic acid), MMlA as raw material 2
(Methyl maleate) or MFmA (methyl fumarate), respectively, according to the composition shown in Table 2,
In the same manner as in Reference Examples 1 to 3, three types of hemiacetate ester group-containing monomers with the abbreviations shown in Table 2, that is, monomer B were synthesized.

[0044]

Production Examples 1 to 10 A flask equipped with a stirrer was charged with a solvent according to the blending compositions shown in Tables 3 to 6, and the temperature was raised to 80 ° C. while stirring and introducing nitrogen gas. Then, a mixed liquid of the monomers (monomers A to C) and the polymerization catalyst was added dropwise thereto over 3 hours, and the temperature was maintained for 5 hours after completion of the addition to complete the polymerization.
Finally, a diluting solvent is added to dilute to contain a silyl ester group and a hemiacetate ester group in the molecule.
0 polymer solutions IX were prepared.

Comparative Production Examples 1 and 2 A flask equipped with a stirrer was charged with a solvent according to the composition shown in Table 6 while stirring and introducing nitrogen gas.
The temperature was raised to 80 ° C. Next, a monomer [monomer A
The mixed solution of (or monomer B), monomer C] and the polymerization catalyst was added dropwise over 3 hours, and the temperature was maintained for 5 hours after the completion of the addition to complete the polymerization. Finally, a diluting solvent is added to dilute, and two polymer solutions XI to XII having only silyl ester groups or only hemiacetate ester groups in the molecule are diluted.
Was manufactured.

In Tables 3 to 6, Monomer B is referred to in Reference Example 1
What was manufactured by -6 was used. Monomer A and Monomer C
And the "AIB" used as the polymerization catalyst.
“N” is as follows. TBSA: Tributyl silyl acrylate TMSA: Trimethyl silyl acrylate TESA: Triethyl silyl acrylate TPSA: Triisopropyl silyl acrylate
TESMA: triethylsilylmethacrylate TBSMMA: tributylsilylmethylmaleate TBSMFA: tributylsilylmethylfumarate MMA: methylmethacrylate VAc: vinyl acetate AIBN: 2,2'-azobisisobutyronitrile

[0048]

[0049]

[0050]

[0051]

Examples 1 to 10 Polymer solutions I to X produced in Production Examples 1 to 10 shown in Table 7 below: 32.8 parts, cuprous oxide 57.41 as an antifouling agent
Part, 1.19 parts of titanium dioxide as a pigment, and Desparon 6900-20X as an anti-sagging agent [Kusumoto Kasei Co., Ltd.
[Production] 10 kinds of coating compositions were prepared by a paint shaker with the composition of 3 parts and xylene 5.6 parts as a solvent.

[0053]

Examples 11 to 31 Using the polymer solutions I to X produced in Production Examples 1 to 10,
Twenty-one kinds of coating compositions were prepared with a paint shaker according to the compounding compositions shown in the following Tables 8 to 13 (the numerical values in the tables are% by weight). In addition, among the compounding ingredients, Desparon A630-20X as an anti-sagging agent is Kusumoto Kasei Co., Ltd.
It is made.

[0055]

[Table 1]

[0056]

[Table 2]

[0057]

[Table 3]

[0058]

[Table 4]

[0059]

[Table 5]

[0060]

[Table 6]

Comparative Examples 1 and 2 Polymer Solutions I to X: Instead of 32.8 parts, the polymer solution XI (Comparative Example 1) and the polymer solution XII (Comparative Example 2) produced in Comparative Production Examples 1 and 2 were used. 2) was used in the same manner as in Examples 1 to 10 except that 32.8 parts were used to prepare two types of coating compositions.

Examples 1 to 31 and Comparative Examples 1 and 2 above
With respect to each coating composition, the coating film consumption test, antifouling performance test, adhesion test and crack resistance test were conducted in the following manner. These results are as shown in Tables 14 to 17 below.

<Coating Film Depletion Test> Each coating composition was sprayed on the front surface of a steel plate (100 mm × 100 mm × 1 mm) having a rustproof coating on the back surface so that the dry film thickness was 200 μm.
It was painted and dried in a room at a temperature of 20 ° C. for 1 week to prepare a test piece. After fixing the above test piece to the outer surface of a cylindrical drum with a diameter of 50 cm, dip it 1 m below the sea surface in Yura Bay, Sumoto City, Hyogo Prefecture, and rotate it with a motor so that the peripheral speed of the drum is 16 knots. The consumed film thickness by 1 every 3 months.
It was measured for 8 months. Also, the average speed of film thickness consumption (μm /
Month) was calculated. The average thickness of coating film consumption is 3 μm
If it is more than / month, it correlates with good antifouling performance.

<Anti-fouling performance test> Each coating composition was coated on a sandblasted steel sheet with a tar vinyl anticorrosive coating in advance (100 mm x 200 mm x 1 mm) on both sides, and the dry film thickness was on one side. Spray coating was applied twice to a thickness of 240 μm, followed by drying for 1 week in a constant temperature and constant humidity chamber at a temperature of 20 ° C. and a humidity of 75% to prepare a test piece. This test piece was immersed in seawater for 24 months in Aioi Bay, Aioi City, Hyogo Prefecture, which is a sea area where biofouling is severe. It was measured.

<Adhesion Test> A blasted steel plate was coated twice with a tar epoxy-based rust preventive paint by spray coating so as to obtain a dry film thickness of 125 μm per time, and further, a tar vinyl-based sealant was applied. -Coating was performed so that the dry film thickness was 70 μm. On top of this, apply each coating composition to a dry film thickness of 10
Spray twice to achieve 0 μm,
A test piece was prepared by drying for 1 week in a constant temperature and humidity room at a temperature of 20 ° C. and a humidity of 75%. This test piece was immersed in artificial seawater and pulled up after 3 months, 6 months, 9 months, 12 months and 18 months, and a 2 mm-interval goggles test [J
IS K5400 (1990) 8.5.2 according to the cross-cut tape method] was carried out. The evaluation of the adhesion was evaluated as ◯ (pass) when the number of adhesions was 25/25 in this test, and was x (failed) when the number of adhesions was 24 or less / 25.

<Crack resistance test> In the adhesion test, when the test piece was pulled up from the artificial seawater, the coating film was visually observed to check for the occurrence of cracks. Those without cracks were marked with O (pass), and those with cracks were marked (fail).

[0067]

[Table 7]

[0068]

[Table 8]

[0069]

[Table 9]

[0070]

[Table 10]

As is clear from the results shown in Tables 14 to 17, the coating compositions of the present invention of Examples 1 to 31 have good coating consumption and the adhesion of organisms in antifouling performance is up to 24 months. It was not observed at all, and neither adhesion nor coating film defect was observed. On the other hand, the coating composition of Comparative Example 1 uses a polymer having a silyl ester group but not a hemiacetate ester group, but the coating film consumption and antifouling performance are both unsatisfactory results. However, there were some defects in adhesion and crack resistance. In addition, the coating composition of Comparative Example 2
Although a polymer having a hemiacetal ester group but not a silyl ester group was used, the coating consumption and antifouling performance were both unsatisfactory results, and there were defects in adhesion and crack resistance. In particular, defects such as blisters, cracks, and peeling were observed on the coating film with time.

[0072]

INDUSTRIAL APPLICABILITY The coating composition of the present invention has good stability during the dispersion step and storage during coating production, and is used for the purpose of preventing marine biofouling from the bottom of the ship, fish nets and cooling. It can be used for underwater structures such as water pipes, as well as for preventing sludge diffusion in marine civil engineering work, and its coating film does not have cracking or peeling, and has a hydrolyzable property that dissolves in the sea uniformly at an appropriate speed. As shown, the excellent antifouling performance can be maintained over a long period of time against the biofouling fouling on the surface of each object described above.

Claims (1)

[Claims] 1. The following general formula (1); (However, in the formula, each of R ^{1 to} R ³ is a group selected from an alkyl group and an aryl group, and may be the same group or different groups. An acryloyloxy group, a methacryloyloxy group, a maleinoyloxy group or a fumaroyloxy group) and the following general formula (2); (In the formula, R ⁴ is an alkyl group, R ⁵ is an alkyl group or a cycloalkyl group, and Y is an acryloyloxy group, a methacryloyloxy group, a maleinoyloxy group or a fumaroyloxy group.) A copolymer of a monomer mixture containing a monomer B and, if necessary, another vinyl monomer C copolymerizable with the monomers A and B, and an antifouling agent as essential components. A coating composition characterized by the above.