JPH11335619A - Antifouling coating composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an antifouling coating composition capable of keeping the antifouling performance over a long period by the slow dissolution of the coating film in seawater after forming a coating film by adding a carboxy- containing monobasic acid to an antifouling coating material composed of specific components. SOLUTION: This antifouling coating composition contains (A) a copolymer of (i) one or more kinds of monomers expressed by the formula (R1 is H or CH3 ; R2 to R4 are each 1-18C alkyl, a cycloalkyl or an aryl) and (ii) one or more kinds of other ethylenic unsaturated monomers copolymerizable with the component (i), (B) a monobasic acid containing carboxy group and (C) a metal-containing antifouling agent. The amount of the component (i) is preferably 5-80 wt.% of the total monomer of the component A and the weight- average molecular weight of the component A is preferably 1,000-100,000. The ratio of the total number of carboxy groups bonded with triorganosilyl groups in the component A to the total number of carboxy groups in the component B is preferably 0.3-3.0.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an antifouling paint composition for preventing marine organisms from adhering to the surface of an underwater object.

[0002]

2. Description of the Related Art Various types of marine organisms adhere to the bottom skin of ships below the sea level, marine structures, fish nets, and other surfaces, which hinders efficient operation of ships. Problems such as a significantly shortened service life occur in structures and fishnets. As a countermeasure, antifouling paint compositions containing various antifouling agents are applied. Typical antifouling paints that have been used in the past include an antifouling agent and a vehicle component consisting of resins such as vinyl resins, alkyd resins, and chlorinated rubbers that are insoluble in seawater, and rosin that is soluble in seawater. Insoluble matrix type antifouling paint,
Further, there is a dissolved matrix type antifouling paint in which a tin-containing resin which is gradually hydrolyzed in sea water is used as a vehicle component and an antifouling agent is added as required.

[0003] However, in the insoluble matrix type antifouling paint, since the antifouling agent elutes together with rosin in seawater, a stable antifouling effect cannot be expected for a long time.
Since the insoluble resin component remaining in the coating film forms a skeleton structure, particularly when applied to a ship, there is a disadvantage that the frictional resistance between seawater and the coated surface increases, resulting in a reduction in speed, an increase in fuel efficiency, and the like. On the other hand, the dissolved matrix type antifouling paint,
Although it has an antifouling effect, it has problems in health and safety and environmental conservation. Accordingly, as an antifouling paint which has solved the problems of the above-mentioned dissolved matrix type antifouling paint, an antifouling paint using a resin containing a triorganosilyl group as a binder has been developed (for example, Japanese Patent Publication No. 5-32433). No. 7
-68467 and JP-A-7-18216). In the coating film formed from the antifouling paint, the triorganosilyl group is gradually desorbed by hydrolysis in seawater,
Since a free carboxyl group is generated and the hydrophilic property is increased, the coating film has a solubility property (abrasiveness) in seawater.
However, an antifouling paint using a resin containing a triorganosilyl group as a binder, when a metal-containing antifouling agent is added, easily reacts with a carboxyl group generated after the triorganosilyl group is hydrolyzed. It has been found that the film has a disadvantage that the polishing property of the film is adversely affected and the antifouling property gradually decreases.

[0004]

SUMMARY OF THE INVENTION The present invention overcomes the drawbacks of conventional antifouling paints and provides various underwater surfaces on objects such as the bottom skin of ships below sea level, marine structures, and fish nets. An object of the present invention is to provide a coating composition that can effectively prevent organisms from adhering for a long period of time.

[0005]

Means for Solving the Problems The present inventors have conducted studies to solve the above problems, and as a result, have found that an antifouling agent containing a copolymer containing a triorganosilyl group and a metal-containing antifouling agent. By adding a carboxyl group-containing monobasic acid to the paint, the coating film gradually dissolves in seawater after the formation of the coating film, so that it has been found that the antifouling performance can be maintained for a long time. The present invention has been completed based on such findings. Accordingly, the present invention provides a compound represented by the formula (I):

[0006]

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Wherein R ₁ is H or CH ₃ ;
₂ , R ₃ and R ₄ each independently represent a group having 1 to 1 carbon atoms.
It is a group selected from the group consisting of eight alkyl groups, cycloalkyl groups and aryl groups. )) And one or more of the other ethylenically unsaturated monomers (B) copolymerizable with the monomer (A).
The present invention provides an antifouling coating composition comprising a copolymer with at least one or more species, (II) a monobasic acid containing a carboxyl group, and (III) a metal-containing antifouling agent.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. Copolymer (I) serving as a binder used in the present invention
Is, for example, a monomer (A) having a triorganosilyl group represented by the above formula and another ethylenically unsaturated monomer (B) copolymerizable with the monomer (A), It is produced by copolymerization according to a conventional method such as polymerization in an organic solvent in the presence of a polymerization initiator. In the above formula representing the monomer (A), R ₂ , R ₃ and R ₄ each independently represent a carbon atom of 1
It is selected from the group consisting of ~ 18 alkyl groups, cycloalkyl groups and aryl groups. The alkyl group may be linear or branched. As the alkyl group, specifically, for example, a methyl group, an ethyl group, a propyl group,
Isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl And the like. Preferred alkyl groups have, for example, 1 to 8 carbon atoms.

Preferred examples of the cycloalkyl group include a cyclohexyl group, a cycloheptyl group, a cyclooctyl group and a cyclononyl group. Further, as the aryl group, for example, a phenyl group, a naphthyl group and the like are preferably mentioned. As the triorganosilyl group, various combinations of the above R ₂ , R ₃ and R ₄ can be selected. Specifically, as the monomer (A), dimethylbutylsilyl acrylate, dimethylhexylsilyl acrylate, dimethyloctylsilyl acrylate, dimethyldecylsilyl acrylate, dimethyldodecylsilyl acrylate, dimethylcyclohexylsilyl acrylate, dimethylphenylsilyl acrylate, Representative examples include dibutylsilyl acrylate, ethyldibutylsilyl acrylate, dibutylhexylsilyl acrylate, dibutylphenylsilyl acrylate, tripropylsilyl acrylate, tributylsilyl acrylate, triphenylsilyl acrylate, and the like, and methacrylates corresponding thereto.

The monomer (B) is used in combination with the above-mentioned monomer (A) to suitably adjust the abrasiveness of the obtained copolymer and, consequently, the antifouling effect. Yes, as long as it has an ethylenically unsaturated bond copolymerizable with the monomer (A), various monomers can be used. Examples of such a monomer (A) include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, hexyl acrylate, octyl acrylate, stearyl acrylate, cyclohexyl acrylate, 2-hydroxyethyl acrylate, dimethylaminoethyl acrylate, Acrylamide, acrylonitrile and the like; and methacrylate corresponding thereto; vinyl acetate, vinyl methyl ether, vinyl ethyl ether, vinyl pyrrolidone and the like are typical examples.

The weight average molecular weight of the copolymer (I) is, for example, from 1,000 to 100,000, especially from 5,000 to 5,000.
It is preferably 0. When the weight average molecular weight is less than 1,000, the polishing properties are too large, and the long-term antifouling property tends to decrease. On the other hand, when the weight average molecular weight is more than 100,000, the polishing properties and the antifouling effect tend to decrease. The weight ratio of the monomer (A) and the monomer (B) constituting the copolymer (I) is as follows:
For example, (5:95) to (80:20), preferably (20:80) to (65:35), are suitable. If the proportion of the monomer (A) is less than the above range, the polishing property is reduced, and the antifouling effect tends to be reduced. On the other hand, if the proportion is too large, the polishing property is too large, and the long-term antifouling property tends to be inferior. It is in.
The carboxyl-containing monobasic acid (I) used in the present invention
As I), for example, monobasic acids represented by the following formula can be mentioned.

X-COOH (where X is an alkyl group, an alkenyl group, a cycloalkyl group, a cycloalkenyl group and an aryl group.) Here, the alkyl group may be straight-chain or branched. Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a t-butyl group, a pentyl group, a hexyl group, and a heptyl group. Preferable examples include an alkyl group such as a group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group and tetradecyl group. Preferred alkyl groups have, for example, 1 to 1 carbon atoms.
There are eight. The alkenyl group may be linear or branched. Examples of the alkenyl group include an alkenyl group corresponding to the above-mentioned alkyl group.

Preferred examples of the cycloalkyl group include a cyclohexyl group, a cycloheptyl group, a cyclooctyl group and a cyclononyl group. Preferable examples of the cycloalkenyl group include those corresponding to the above cycloalkyl group. Further, a ring system in which several cycloalkyl groups are condensed, for example, a ring system constituting abietic acid and the like can be mentioned. Further, as the aryl group, for example, a phenyl group, a naphthyl group and the like are preferably mentioned. In addition, each of the above functional groups may optionally have a substituent. Examples of such a substituent include a halogen atom (chlorine, bromine, fluorine atom, and the like), a lower alkyl group such as a methyl group and an ethyl group, and a hydroxyl group.

Examples of such a monobasic acid include acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, and the like.
Isovaleric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, undecylic acid, lauric acid,
Tridecylic acid, myristic acid, pentadecylic acid, palmitic acid, heptadecylic acid, stearic acid, nonadecanoic acid, arachiic acid, linoleic acid, linolenic acid, oleic acid, arachidonic acid, lactic acid, pivalic acid, dimethylacetic acid,
Examples include cyclohexanecarboxylic acid, 12-hydroxystearic acid, fluoroacetic acid, chloroacetic acid, parvic acid, abietic acid, and naphthenic acid. These monobasic acid compounds can be used alone or in combination of two or more. As the metal-containing antifouling agent (III) used in the present invention, various metal-containing antifouling agents conventionally used in antifouling paints can be used without particular limitation. Specific examples thereof include cuprous oxide, basic copper carbonate, copper thiocyanate, copper hydroxide, cuprous rhodan, manganese ethylenebisdithiocarbamate, zinc dimethyldithiocarbamate, zinc ethylenebisdithiocarbamate, and 2-pyridine. Thiol-1
-Zinc oxide and the like. These metal-containing antifouling agents can be used alone or in combination of two or more.

Various antifouling agents other than the above metal-containing antifouling agent can be used in combination with the coating composition of the present invention, if necessary. A specific example is 2-methylthio-4-t
-Butylamino-6-cyclopropylamino-s-triazine, 2,4,5,6-tetrachloroisophthalonitrile, N, N-dimethylchlorophenylurea, 4,5
-Dichloro-2-N-octyl-3 (2H) isothiazolone, N- (fluorodichloromethylthio) phthalimide, N- (3,4-dichlorophenyl) -N, N-dimethylurea, 2,4,6-trichlorophenylmaleimide And the like. Further, the antifouling coating composition of the present invention, if necessary, as a component other than the above components, an extender pigment, a coloring pigment, a plasticizer, an antifoaming agent, an antisettling agent,
Various additives such as a leveling agent, other resins, organic solvents and the like can be blended.

The antifouling coating composition of the present invention comprises the above-mentioned copolymer (I), monobasic acid (II) and metal-containing antifouling agent (III) as essential components. During the minute,
The copolymer (I) is 15 to 70% by weight, preferably 2% by weight.
0 to 50% by weight is suitable. The coating solids content is usually 30 to 95% by weight, preferably 60 to 85% by weight, based on the weight of the antifouling coating composition.
Therefore, other than the solid content of the antifouling coating composition, the solvent consists of a solvent. Examples of the solvent include hydrocarbons such as xylene and toluene, ketones such as methyl ethyl ketone and methyl-butyl ketone, and esters such as ethyl acetate and methyl acetate. And ethers such as ethyl ether and butyl ether. The monobasic acid (II) has a total number of carboxyl groups contained in the monobasic acid (II) with respect to the total number of carboxyl groups to which the triorganosilyl group contained in the copolymer (I) is bonded, (0.3 to 3.0), and preferably a ratio that becomes (0.5 to 1.5) is appropriate.

The amount of the metal-containing antifouling agent (III) is usually from 10 to 60% by weight, preferably from 20 to 50% by weight, based on the weight of the solid content of the paint. If the amount of the copolymer (I) is less than the above range, the strength as an original coating film cannot be obtained.
The amount of I) tends to decrease, and the antifouling property tends to decrease. If the amount of the monobasic acid (II) is less than the above range, the antifouling property tends to decrease. Monobasic acid (I
The cause of the decrease in the antifouling property when the amount of I) is small is not clear, but the triorganosilyl group in the copolymer (I) has a carboxyl group generated after hydrolysis and a metal-containing antifouling agent. It is presumed that (III) partially reacts and inhibits the solubility of the coating film.

When the amount of the metal-containing antifouling agent (III) is less than the above range, the antifouling property tends to decrease, and when the amount is too large, the strength of the coating film tends to decrease. The antifouling paint composition of the present invention is prepared by mixing or dispersing the above components in a lump or divided manner with a usual paint production apparatus such as a ball mill or a disper. The antifouling coating composition of the present invention prepared as described above, as it is, or after adjusting the viscosity with a solvent to improve the coating workability, airless spray coating, air spray coating, roller coating, brush coating, etc. Apply to objects such as marine structures. The antifouling coating composition of the present invention is preferably applied so as to have a thickness of about 30 μm to 300 μm after drying.

[0019]

The present invention will be described in more detail with reference to the following examples. In the examples, “parts” and “%” are based on weight. <Preparation of Varnish of Copolymers (I) -1 and (I) -2 and Tin-Containing Copolymer) In a four-necked flask equipped with a stirrer, a thermometer, and a reflux tube, 90 parts of xylene was charged, and the temperature was adjusted. The mixture was kept at 100 ° C., and a mixture of 60 parts of tri-n-butylsilyl methacrylate, 40 parts of methyl methacrylate, and 3 parts of azoisobutyronitrile was added dropwise over 3 hours while stirring to cause a reaction. After holding for 1 hour, a mixture of 1 part of azoisobutyronitrile and 10 parts of xylene was added to 1 part of
The mixture was dropped over a period of time and reacted to prepare a varnish of copolymer (I) -1.

A varnish of copolymer (I) -2 and a tin-containing copolymer was prepared in the same manner except that the components shown in Table 1 were changed.

[0021]

Table 1 (Unit: parts) Copolymer (I) Copolymer (I) Tin-containing copolymer -1 varnish -2 varnish Varnish Tri-n-butylsilyl 60 methacrylate tri-isopropyl 55 silyl methacrylate tri-n-butyltin 65 methacrylate methyl methacrylate 40 30 15 ethyl acrylate 15Butyl acrylate 20 Azoisobutyronitrile 3 3 3 Xylene 90 90 90 Azoisobutyronitrile 1 1 1Xylene 10 10 10 Solid content (%) 50 50 50 Weight average molecular weight of copolymer 25000 28000 45000

Examples 1-3 and Comparative Examples 1-2 The compositions shown in Table 2 below were kneaded and dispersed to produce antifouling paints of Examples 1-3 and Comparative Examples 1-2. Each of these antifouling paints was applied to a steel plate coated with a rust preventive paint by air spraying so as to have a dry film thickness of 300 μm, and dried. The obtained test plate was subjected to an abrasion test and an antifouling test.
Table 3 shows the results. In addition, each test was performed based on the following method. <Abrasiveness test> Rotor test (25 ° C, 15 knots)
Thereafter, the film thickness was measured with a micrometer, and the difference from the film thickness before the test was calculated. <Antifouling test> In Toba Bay, Toba City, Mie Prefecture, a test plate was submerged in the sea and the appearance of the coating film was observed. Evaluation criterion 5: No deposit was observed on the test plate. 4: Adhesion of thin slime was observed on the test plate. 3: Thick slime adhered to the test plate. 2: Adherence of large animals and plants is observed. 1: Many large animals and plants adhere.

[0023]

Table 2 (Unit: parts) Coating composition Example Comparative Example 1 2 3 1 2 Copolymer (I) -1 varnish 40 40 40 Copolymer (I) -2 varnish 40 Tin-containing copolymer varnish 40 Oleic acid 15 15 Palmitic acid 10 Cuprous oxide 40 40 40 40 40 Zinc pyrithione 2 2 2 2 2 Petal 10 10 10 10 10 Talc 3 3 3 3 3 Xylene 5 5 5 5 5 Ratio of carboxyl group Note ¹⁾ 1.3 1.2 0.9 0 Note 1) Ratio of the total number of carboxyl groups of monobasic acid to the total number of carboxyl groups to which triorganosilyl groups contained in the copolymer are bonded

[0024]

Table 3 Example 3 Comparative Example 1 2 3 1 2 3 months 30 35 28 33 22 Abrasiveness (μm) 6 months 58 72 55 58 47 9 months 85 100 80 70 74 12 months 114 135 108 81 97 3 months 5 5 5 5 5 6 months 5 5 5 5 5 Antifouling 9 months 5 5 5 5 5 12 months 5 5 5 4 5 18 months 5 5 5 3 5 24 months 4 4 4 3 4

As is clear from Table 3, Examples 1 to 3, which are the antifouling paint compositions of the present invention, are known as conventional antifouling paints having excellent antifouling properties. It had the same abrasion and long-term antifouling properties as Comparative Example 2 containing tin with noness. On the other hand, Comparative Example 1 in which a monobasic acid containing a carboxyl group was not blended was inferior in abrasive properties and antifouling properties.

[0026]

The coating film formed from the antifouling coating composition of the present invention has good polishing properties and can effectively prevent various marine organisms from adhering for a long period of time.

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Hiroharu Sasaki 7-1414-46 Shimonagata, Nishinasuno-cho, Nasu-gun, Tochigi Prefecture

Claims (3)

[Claims] (I) The following formula: (Wherein R ₁ is H or CH ₃ , and R ₂ , R ₃ and R ₄ are each independently selected from the group consisting of alkyl groups having 1 to 18 carbon atoms, cycloalkyl groups and aryl groups. Or two or more kinds of the monomer (A) represented by the formula (1) and one of the other ethylenically unsaturated monomers (B) copolymerizable with the monomer (A). Or two or more copolymers, (II) a monobasic acid containing a carboxyl group, and (II)
I) An antifouling coating composition comprising a metal-containing antifouling agent. 2. The antifouling paint composition according to claim 1, wherein the amount of the monomer (A) is 5 to 80% by weight of the total monomers of the copolymer (I). 3. The ratio of the total number of carboxyl groups to which the triorganosilyl groups contained in the copolymer (I) is bonded to the total number of carboxyl groups contained in the monobasic acid (II) is 0. 3. The antifouling coating composition according to claim 1, wherein the composition is from 0.3 to 3.0.