JPH07150077A - Varnish composition for coating material and antifouling coating composition - Google Patents

Abstract

PURPOSE:To obtain a varnish composition for coating material which is used for preventing underwater organisms from attaching to an underwater structure such as a ship, a fishing net, a drain, etc., and contains a carboxyl group- containing biodegradable polymer and a triazole compound. CONSTITUTION:This composition contains (A) a carboxyl group-containing biodegradable polymer (a polymer preferably containing an ester bond in the main chain obtained by polymerizing an organic acid monomer such as malic acid, tartaric acid, citric acid or isocitric acid) and (B) a triazole compound (e.g. 1,2,3-benzotriazole or 4-amino-1,2,4-triazole).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paint varnish composition and an antifouling paint composition for the purpose of preventing adhesion of aquatic organisms to underwater structures such as ships, fishing nets and drainage channels.

[0002]

2. Description of the Related Art A large number of marine organisms such as barnacles, ascidians, serpras, blue mussels, and sea lions inhabit seawater. When structures such as ships, fishing nets, drainage channels, etc. are installed or put in service in the sea, marine organisms adhere and grow to cause various damages. For example, if marine organisms adhere to the bottom of the ship, frictional resistance with seawater increases, causing a decrease in navigation speed, and fuel consumption increases to maintain a constant speed, which is not economically preferable. In addition, when marine organisms attach to a fishing net for aquaculture, the net may be closed and the seafood may be killed.

Conventionally, in order to prevent marine organisms from adhering to such marine structures, an antifouling paint containing a homopolymer or copolymer of an organic tin-containing unsaturated monomer as a resin component (Japanese Patent Publication No. 40-21426, Japanese Patent Publication No. 44-957.
9, Japanese Patent Publication No. 46-13392, Japanese Patent Publication No. 49
-20491, Japanese Patent Publication No. 51-11647,
Japanese Patent Publication No. 51-12049, Japanese Patent Publication No. 52-4817
No. 0, etc.) was painted. In these polymers, the organic tin part is hydrolyzed by seawater (pH 8.0 to 8.3), not only the organic tin acts as an antifouling agent, but also the seawater-solubilized polymer surface is gradually moved by seawater. By eroding and exposing the new coating film surface, a long-term stable antifouling effect is exhibited. However, organotin released from these paints into seawater is not very easy to decompose and accumulates not only in marine organisms but also in the human body due to the food chain, causing damage such as malformation, so it is extremely dangerous, The use of organotin compounds has become limited. Further, a copolymer eluted into seawater by hydrolysis is not preferable for the ecosystem.

It has been desired to develop a resin for an antifouling paint which can achieve stable antifouling property for a long period of time in place of these highly dangerous organotin resins. Ideally, the same hydrolysis type as the organotin resin is preferable, but a proposal using a hydrophilic or water-repellent resin has also been made (JP-A-62-2).
No. 90768, No. 62-13471, No. 58-180565, No. 57-6767.
No. 2, etc.). However, it is difficult to realize long-term stable antifouling property only by the properties of hydrophilicity and water repellency.

Therefore, a resin having various special carboxylic acid esters in its side chain as a hydrolyzable resin has been proposed (JP-A-60-500452, JP-A-2-69576, JP-A-2-69576). JP-A-63-215780, JP-B-55-39271, and JP-A-62-57.
No. 464, Japanese Patent Publication No. 61-3830), but the effect is not completely satisfactory.

On the other hand, JP-A-51-124130
Japanese Unexamined Patent Publication No. 62-135575 and Japanese Patent Publication No. 62-501.
It has been proposed in Japanese Patent No. 293 etc. to use a copolymer of a derivative having a free carboxyl group for this purpose. It is expected that this copolymer, unlike the organic tin-based resin, does not have toxicity itself and is excellent in self-disintegrating property.
On the other hand, it has been proposed to use a biodegradable polymer as a copolymer of a derivative having a free carboxyl group (Japanese Patent Laid-Open No. 4-120183). If this is used, the copolymer will be dissolved in seawater and then decomposed by microorganisms to become a completely harmless natural product. However, when it is used for an antifouling paint, it has a fatal drawback that it causes thickening-gelation by kneading with a copper compound currently used as a poison.

[0007]

DISCLOSURE OF THE INVENTION The present invention does not have the dangers of organotin copolymers, exhibits extremely high safety to humans and seafood, and is kneaded with a copper compound. Provided are an excellent varnish composition for paints and an antifouling paint composition which do not gel even if they are used.

[0008]

DISCLOSURE OF THE INVENTION The inventors of the present invention have the object of solving the above problems and developing an antifouling paint which is excellent in the property of preventing the adhesion of marine organisms and has no danger. As a result of earnest research, the present invention has been completed. The present invention relates to the following (1) to (4). (1) A coating varnish composition containing a biodegradable polymer having a carboxyl group and a triazole compound. (2) The coating varnish composition according to (1), wherein the biodegradable polymer has an ester bond in the main chain. (3) The biodegradable polymer is a polymer obtained by polymerizing at least one organic acid monomer selected from malic acid, tartaric acid, citric acid, and isocitric acid, or is copolymerizable therewith. The varnish composition for coating according to the above (2), which is a polymer obtained by polymerizing one or more other organic acids. (4) An antifouling coating composition comprising the varnish composition for coating according to (1), (2) or (3) above and an antifouling agent containing a copper compound as a main component.

The biodegradable polymer used in the present invention has a carboxyl group in its side chain. Specific examples include those having an ester bond in the main chain.
More specifically, examples thereof include those obtained by polycondensing one or more kinds of organic acid monomers selected from malic acid, tartaric acid, citric acid and isocitric acid. Such a polymer is a homopolymer of any of the above organic acid monomers,
It may also be a copolymer. Further, the polymer may be a copolymer with one or more other organic acids copolymerizable with one or more of the above-mentioned organic acid monomers.

Other organic acids which can be copolymerized include:
Biologically-derived, oxyacids and sugar acids having a hydroxyl group and a carboxyl group are preferable, oxyacids include glycolic acid, lactic acid, salicylic acid, mandelic acid, and the like, and sugar acids include glucuronic acid, galacturonic acid, and mannuronic acid. , Gluconic acid, glucaric acid, etc. When these other copolymerizable organic acids are used, the amount thereof can be arbitrarily selected with respect to the total amount of organic acids, but preferably 1 to
It is 90 mol%, particularly preferably 5 to 80 mol%. 9
If it exceeds 0 mol%, it is difficult to obtain a resin exhibiting sufficient coating film exhaustion. When the organic acid is an optically active substance, D-form,
It may be either L-form or racemic form.

The above-mentioned polymer is prepared by preparing malic acid, tartaric acid,
It can be carried out by a synthetic route such as thermal polycondensation of citric acid or isocitric acid or other organic acid copolymerizable therewith, ring-opening polymerization via a lactone or a cyclic diester dimer. The reaction temperature can be carried out within a range in which precipitation of organic acid is not observed. These various synthetic routes are described in Oil Chemistry, Vol. 35, p. 937, (1986), Polymers, Vol. 44, p. 701, (1987), Macromol. Chem., 190.
Vol., Page 1523, (1989), JP-A-63-92641, and the like. As the polymer, a biosynthetic substance or a commercially available product may be used. A specific manufacturing method will be described below.

For the thermal polycondensation of malic acid, for example, dimethyl sulfoxide is used as a solvent, and the reaction temperature is 60 to 120 ° C., preferably 80 to 100 ° C. for 3 to 7
After prepolymerization under reduced pressure of several tens of mmHg for 10 hours, further 10 mmHg
The following is preferably 10 under reduced pressure of 0.1 to 0.3 mmHg.
Polymerization and distillation of dimethyl sulfoxide for 90 hours, preferably 20 to 80 hours can be carried out to obtain poly (α, β-malic acid). In bulk thermal polycondensation of malic acid, after heating and melting malic acid at 140 ° C, 10
Polycondensation is carried out at 0 to 160 ° C, preferably 120 to 140 ° C. Polymerization time is 5 to 30 hours, preferably 10 to 25
It's time. The inside of the reaction system must be kept under reduced pressure of 1 mmHg or less, preferably 0.5 to 1.0 mmHg.

Further, as ring-opening polymerization via a lactone or a cyclic diester dimer, for example, in the case of poly (β-malic acid), benzyl malolactonate is prepared from malic acid and subjected to ring-opening polymerization to form β. It is possible to obtain poly (β-malic acid) by catalytic reduction after making poly-α-benzylmalolactonate. Ring-opening polymerization can be carried out in bulk or in a solvent. As the polymerization catalyst, betaine, triethylamine, betaine triethyl, ammonium benzoate, ferric chloride, triethylaluminum, etc. can be used, and the reaction temperature is 0 to 80 ° C, preferably 20 to 60 ° C. The reaction time is 3 to 21 days, preferably 7-14 days.

In the case of a poly (α-malic acid-lactic acid) copolymer, malic acid and lactic acid are maled dibenzyl ester of cyclic diester dimer and L-lactide, which are subjected to ring-opening copolymerization to obtain α. -Poly-β-benzylmalate-lactic acid copolymer, and then catalytically reduced to give poly (α-
A malic acid-lactic acid) copolymer can be obtained. Ring-opening polymerization can be carried out in bulk or in a solvent. An organotin catalyst such as tin octylate or tin dibutyl laurate can be used as the polymerization catalyst. Reaction temperature is 100
˜250 ° C., preferably 110˜220 ° C. The reaction time is 6 to 12 hours, preferably 8 to 10 hours.
The molecular weight of the resulting biodegradable polymer is not particularly limited, but the number average molecular weight is preferably 500 to 200,000, more preferably 1,000 to 50 from the viewpoint of various properties as a coating resin. 1,000.

The solvent is not particularly limited as long as it dissolves the biodegradable polymer, and it can be used alone or as a mixture of two or more kinds. For example, ethanol, alcohol solvents such as n-propanol, isopropanol and benzyl alcohol, cyclic ether solvents such as tetrahydrofuran and dioxane, ester solvents such as ethyl acetate and butyl acetate, ketone solvents such as acetone, methyl ethyl ketone and cyclohexanone, Aprotic polar solvents such as dimethylsulfoxide and dimethylformamide can be mentioned. In addition, water that does not cause a problem of environmental pollution can also be used as one of the solvents.

Examples of the triazole compound added to the solution of the biodegradable polymer in the present invention include a benzotriazole derivative, an amino-substituted triazole derivative, and other triazole derivatives.

The benzotriazole derivative is 1,
2,3-benzotriazole, 1-methyl-1,2,3
-Benzotriazole, 1-phenyl-1,2,3-benzotriazole, 2-phenyl-1,2,3-benzotriazole, 4-chloro-1,2,3-benzotriazole, 4-nitro-1,2 , 3-benzotriazole, 5-methyl-1,2,3-benzotriazole, 5
-Ethyl-1,2,3-benzotriazole, 5-propyl-1,2,3-benzotriazole, 5-isobutyl-1,2,3-benzotriazole, 5-methoxy-
1,2,3-benzotriazole, 5-chloro-1,
2,3-benzotriazole, 5,6-dimethyl-1,
There are 2,3-benzotriazole, 1,2,3-benzotriazolecarboxylic acid and ester derivatives thereof, N-dialkylaminomethyl-1,2,3-benzotriazole and the like. Examples of the amino-substituted triazole include 4-amino-1,2,4-triazole and 3-amino-1H-
1,2,4-triazole and the like. Other triazole derivatives include 1,2,3-triazole, 1
-Methyl-1,2,3-triazole, 1-phenyl-
1,2,3-triazole, 1-benzyl-1,2,3
-Triazole, 2-methyl-1,2,3-triazole, 2-phenyl-1,2,3-triazole, 2-benzyl-1,2,3-triazole, 4-methyl-1,
2,3-triazole, 4-phenyl-1,2,3-triazole, 4-hydroxy-1,2,3-triazole, 4,5-dimethyl-1,2,3-triazole, 4
-Methyl-2-phenyl-1,2,3-triazole,
4,5-Dimethyl-2-phenyl-1,2,3-triazole, 1,5-diphenyl-1,2,3-triazole, 1,2,4-triazole, 1-methyl-1,2,
4-triazole, 1-phenyl-1,2,4-triazole, 3-methyl-1,2,4-triazole, 3-
Phenyl-1,2,4-triazole, 3-chloro-
1,2,4-triazole, 3-bromo-1,2,4-
Triazole, 3,5-dimethyl-1,2,4-triazole, 3,5-diethyl-1,2,4-triazole, 1,3-diphenyl-1,2,4-triazole,
1,5-diphenyl-1,2,4-triazole, 3,
Examples include alkyl, aryl, aralkyl, halogen or hydroxy substituted triazole derivatives such as 5-diphenyl-1,2,4-triazole. In addition to these, any commonly known triazole compound can be used. The amount used is not particularly limited, but it is preferably used in the range of 0.1 to 50% by weight based on the solid content of the polymer. If it is less than 0.1% by weight, there is almost no effect of addition, and it is easy to increase the viscosity due to coating with a copper compound.
When it exceeds the weight%, it becomes difficult to form a good coating film. Further, the coating varnish composition of the present invention may be mixed with other polymers to the extent that the effects of the present invention are not impaired. The above-mentioned varnish composition for paints can be made into an antifouling paint composition by adding a colorant such as a known pigment, various antifouling agents, and various additives (a filler, a dispersant, an anti-sagging agent, etc.). .

Examples of the copper compound which is the antifouling agent used in the antifouling coating composition of the present invention include cupric chromate, cupric ferrocyanate, cupric quinoline, cupric δ-hydroquinone, Cupric oleate, cupric nitrate, cupric phosphate,
Examples include cupric tartrate, cuprous oxide, copper rhodanide, copper-nickel solid solution alloys, cuprous iodide and cuprous sulfite. Other typical inorganic antifouling agents include zinc oxide, zinc chromate, and strontium chromate, and organic antifouling agents include 2,4,5,6-tetrachloroisophthalonitrile, N, N. -Dimethyldichlorophenylurea,
4,5-Dichloro-2-n-octyl-3 (2H) -isothiazolone, zinc dimethyldithiocarbamate, 2
-Methylthio-4-t-butylamino-6-cyclopropylamino-s-triazine, N- (fluorodichloromethylthio) phthalimide, N, N'-dimethyl-N '
-Phenyl- (N-fluorodichloromethylthio) sulfamide, 2-pyridinethiol-1-oxide zinc salt, tetramethylthiuram disulfide, 2,4,6
-Trichlorophenylmaleimide, 2,3,5,6-tetrachloro-4- (methylsulfonyl) pyridine, 3
-Iodo-2-propynylbutylcarbamate, diiodomethylparatolylsulfone, bisdimethyldithiocarbamoyl zinc ethylene bisdithiocarbamate, pyridine-triphenylborane and the like. The amount of these antifouling agents used is not particularly limited, but is preferably 1 to 500% by weight, and particularly preferably 50 to 450% by weight based on the solid content of the entire polymer.
Weight percent is preferred. If it is less than 1% by weight, it hardly shows the effect as an antifouling agent, and if it exceeds 500% by weight, it is difficult to form a good coating film. Further, the combined use of an organic tin compound, a triazine compound, an organic sulfur compound or the like as an antifouling agent does not hinder at all.

As the pigment which is an adhesive, inorganic pigments such as titanium oxide (titanium white), iron oxide and carbon black, and organic pigments such as azo, cyanine, phthalocyanine and quinacridone pigments can be used. Usually, an inorganic pigment is used. The amount of the colorant used is not particularly limited and may not be necessary in some cases, but when used, it is preferably 200% by weight or less based on the solid content of the entire polymer. If it exceeds 200% by weight, the stability as a coating film tends to be poor.

As the extender, there are calcium carbonate, barium sulfate, magnesium oxide, alumina and the like. The amount of the extender is not particularly limited, and it may not be necessary to use the extender. It is preferably used in the range of 100% by weight or less based on the solid content of the polymer. If it exceeds 100% by weight, the stability as a coating film tends to be poor.

The dispersion or anti-sagging agent may be an inorganic dispersion or anti-sagging agent such as silica gel type, bentonite type, kaolinite type, talc type, hectorite type, montmorillonite type, saponite type or beidellite type, or fatty acid amide type. , Fatty acid ester type, polyethylene oxide type, sulfate type anion activator, polycarboxylic acid amine salt type, polycarboxylic acid type, polyamide type, high molecular weight polyether type, acrylic copolymer type, special silicone type, etc. There is a dispersant or anti-sagging agent. The amount used is not particularly limited, but is 0.0 with respect to the solid content of the entire polymer.
It is preferably used in the range of 1 to 100% by weight.
If it is less than 0.01% by weight, the effect of addition tends not to appear, and if it exceeds 100% by weight, the stability as a coating film tends to be poor. Further, rosin, gum rosin, wood rosin, tall oil rosin and the like can be used in combination as the dissolution aid. The antifouling paint composition of the present invention thus obtained is useful as a ship bottom paint, a fishing net paint, and the like.

[0022]

EXAMPLES Next, the present invention will be explained by examples.

Production Example 1 [Production of poly (α, β-malic acid)] D-L-malic acid (5.0 g) and dimethyl sulfoxide (2.5 g) were weighed in a Claisen flask, dissolved by heating and then heated to 50 mmHg in a nitrogen atmosphere. Prepolymerization was carried out at 90 ° C. for 5 hours. Next, polymerization was further performed at 0.3 mmHg and 90 ° C. for 56 hours and dimethyl sulfoxide was distilled off to obtain poly (α, β-malic acid) as a white solid. The number average molecular weight of the polymer was 3,000 (value measured by gel permeation chromatography and converted into standard polystyrene. The same applies hereinafter).

Production Example 2 [Production of poly (β-malic acid)] In a four-necked flask equipped with a stirrer, a condenser, a nitrogen gas introducing tube, and a thermometer, 75.8 g of maleic anhydride and 30% hydrobromic acetic acid were added. 250 g of the solution was weighed and stirred and reacted for 4 hours under ice cooling. Then, acetic acid and excess hydrogen bromide were distilled off under reduced pressure at 40 ° C., and the residue was distilled under reduced pressure in a nitrogen atmosphere to obtain bromosuccinic anhydride. Bromo-succinic anhydride 90.
Weigh out 0 g and 53.8 g of benzyl alcohol,
Add 1 drop of concentrated sulfuric acid as a catalyst and use a magnetic rotor at room temperature
After stirring for an hour, benzyl hydrogen bromosuccinate was obtained. 120.6 g of benzyl hydrogen bromosuccinate was weighed into a four-necked flask equipped with a stirrer, a condenser, and a thermometer, and 210 ml of a 1M sodium carbonate aqueous solution was stirred.
Neutralize by the addition of 250 ml of ether and 30 ° C.
The reaction was carried out for 5 hours with stirring, and the produced lactone was extracted into the ether layer. It should be noted that 0.5 hours and 1.
After 5 hours, 125 ml of ether was added, and the reaction solution was acidified by desorption of hydrogen bromide in the reaction process.
It was neutralized by adding an aqueous solution of sodium carbonate M.
After the reaction was completed, the ether layer was dried over anhydrous sodium sulfate, the ether was distilled off, and the residue was purified by column chromatography to obtain benzylmalolactonate. 2.06 g of benzyl malolactonate and 0.0012 g of betaine were weighed and mixed in a glass reaction tube, which was replaced with argon and sealed, and polymerization was carried out at 40 ° C. for 14 days.
Poly (β-benzyl malate) was obtained. 1% by weight of 2.00 g of the obtained poly (β-benzyl malate) was dissolved in a mixed solvent of ethanol / ethyl acetate (1: 1 vol / vol).
It was a solution. 10% palladium on carbon 1.00
g was added, catalytic hydrogenation was carried out to debenzylate, then the catalyst was filtered off, the solvent and the produced toluene were distilled off under reduced pressure, and the residue was dried under reduced pressure to obtain poly (β-malic acid) in the form of a white powder.
The number average molecular weight of the polymer was 5,000.

Production Example 3 [Production of poly (α-malic acid-lactic acid) copolymer] L-aspartic acid and benzyl alcohol were reacted at room temperature under a sulfuric acid catalyst to obtain β-benzyl-L-aspartate, and further 1N. Reaction with sulfuric acid and sodium nitrite gave β-benzyl-L-malate. Obtained β-benzyl-L
-0.12 g of zinc oxide was added to 5.9 g of malate, reacted under reduced pressure (20 to 25 mmHg) at 200 ° C. for 8 hours, and further reacted at 0.1 mmHg for 2 hours. After the reaction,
The catalyst was removed by filtration and purified by column chromatography to obtain a cyclic dimer malide dibenzyl ester.
1.2 g of malide dibenzyl ester in a glass reaction tube
And L-lactide 0.42 g and tin octylate 0.00
After weighing 14 g and mixing, the mixture was tightly capped and reacted at 180 ° C. for 48 hours to give poly (β-benzylmalate-lactic acid).
A copolymer was obtained. Next, 0.62 g of the obtained poly (β-benzylmalate-lactic acid) copolymer was dissolved in 10 ml of ethyl acetate, and 10% palladium carbon 0.1% was added thereto.
8 g was added, catalytic hydrogenation was carried out to debenzylate, then the catalyst was filtered off, the toluene produced was distilled off under reduced pressure and dried under reduced pressure to obtain a poly (α-malic acid-lactic acid) copolymer in the form of a white powder. . The average molecular weight of the polymer was 14,000.

Examples 1 to 3 Each of the polymers produced in the above Production Examples 1 to 3 was dissolved in ethyl acetate or acetone to produce a varnish. The formulation is shown in Table 1.

[Table 1] For each varnish produced, 250 mg of 3-amino-1H-1,2,4-triazole was added to a varnish corresponding to a resin solid content of 25 g, and the mixture was kneaded and stirred using a homogenizer to prepare a coating varnish composition (hereinafter, (Abbreviated as varnish composition) was prepared. Further, 75 g of cuprous oxide (purity 90% by weight or more, powder) was added to this varnish composition, and the mixture was kneaded and stirred using a homogenizer to prepare an antifouling coating composition. In addition, Example 1 uses the varnish 1, Example 2
Is the one using varnish 2, and Example 3 is the one using varnish 3.

Example 4 Varnish 1 was prepared by dissolving the polymer prepared in Preparation Example 1 in acetone according to Table 1. Regarding the manufactured varnish, 250 mg of 1,2,4-triazole was added to a varnish corresponding to a resin solid content of 25 g, and the mixture was kneaded and stirred using a homogenizer to prepare a varnish composition. Further, 75 g of cuprous oxide (purity 90% by weight or more, powder) was added to this varnish composition, and the mixture was kneaded and stirred using a homogenizer to prepare an antifouling coating composition.

Example 5 A varnish 1 was prepared by dissolving the polymer prepared in Preparation Example 1 in acetone according to Table 1. About the manufactured varnish, 1,2,3-benzotriazole (250 mg) was added to a varnish corresponding to a resin solid content of 25 g, and the mixture was kneaded and stirred using a homogenizer to prepare a varnish composition. Further, cuprous oxide (purity 90% by weight or more, powder) 7 was added to the varnish composition.
5 g was added, and the mixture was kneaded and stirred using a homogenizer to prepare an antifouling coating composition.

Comparative Examples 1 to 3 Each of the polymers produced in Production Examples 1 to 3 was dissolved in ethyl acetate or acetone according to Table 1 to produce a varnish. About each varnish produced, 75 g of cuprous oxide (purity 90% by weight or more, powder) was added to a varnish corresponding to a resin solid content of 25 g, and the mixture was kneaded and stirred using a homogenizer to prepare an antifouling coating composition.

Storage stability test After the antifouling coating compositions prepared in Examples 1 to 5 and Comparative Examples 1 to 3 were left at room temperature overnight, the state of the coating was observed and the viscosity was measured at 25 ° C. The antifouling coating composition was sealed in a sample bottle and stored in a constant temperature bath at 40 ° C. for 20 days. After storage, the state of the paint was observed and the viscosity was measured at 25 ° C. The results are shown in Table 2. After the storage, the paint in which the paint condition was very smooth and good was evaluated as ◯, and the pudding-like or paint in which impurities remained and which was not smooth was marked as x.

[Table 2] As is clear from Table 2, the antifouling coating composition prepared using the varnish composition of the present invention showed almost no increase in viscosity even when kneading with cuprous oxide. On the other hand, it was found that the coating material to which the triazole compound was not added was gelated into a pudding-like state and remarkably thickened.

Coating Film Consumability Test A coating film prepared by using the varnish composition of the present invention has a property of gradually becoming water-soluble and eluting under weak alkaline conditions. This fact is shown in the following experiment. The varnish compositions prepared in Examples 1 to 5 were applied on a polypropylene plate having a length of 150 mm and a width of 100 mm to give a dry film thickness of 50 μm, and the mixture was allowed to stand at room temperature for 2 days to remove the solvent component and measure the initial weight. . Next, this polypropylene plate was immersed in 1750 cm ^{3 of} an alkaline buffer solution of pH 10.2, and after 24 hours at 45 ° C., the polypropylene plate was taken out, washed with water and dried, and the final weight was measured. From this difference in weight, the hydrolyzability was measured as the amount of coating reduction. The results are shown in Table 3.

[Table 3] From this experimental result, it is shown that the varnish composition of the present invention has a good self-disintegrating property. Therefore, it was found that the self-disintegrating antifouling coating composition was very good.

[0032]

EFFECTS OF THE INVENTION The varnish composition for coating materials and the antifouling coating composition of the present invention do not have the dangers of organotin copolymers,
Moreover, it shows extremely high safety for human body and seafood,
Furthermore, it is possible to form an excellent coating film that does not gel even when kneaded with a copper compound.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroyuki Tanaka 4-13-1, Higashimachi, Hitachi City, Ibaraki Prefecture Hitachi Chemical Co., Ltd. Ibaraki Research Institute

Claims (4)

[Claims] 1. A varnish composition for coating material, which comprises a biodegradable polymer having a carboxyl group and a triazole compound. 2. The coating varnish composition according to claim 1, wherein the biodegradable polymer has an ester bond in the main chain. 3. The biodegradable polymer is malic acid, tartaric acid,
A polymer obtained by polymerizing one or more kinds of organic acid monomers selected from citric acid and isocitric acid, or a polymer obtained by polymerizing one or more kinds of other organic acids copolymerizable therewith. The varnish composition for coating according to claim 2, which is a united body. 4. An antifouling coating composition comprising the varnish composition for coating according to claim 1, 2 or 3 and an antifouling agent containing a copper compound as a main component.