JPH10306240A - Composition for antifouling coating material and antifouling coating material using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition capable of providing excellent effects on fouling prevention by fouling organisms sticking to ships, marine structures, etc., by including a specific antifouling agent and a prescribed resin. SOLUTION: This composition comprises (A) 10-500 pts.wt. of a thiocyanic acid compound (preferably methylene bisthiocyanate) and (B) 100 pts.wt. of a polyester resin containing >=90 mol.% of lactic acid residue in the resin, L-lactic acid residue/D-lactic acid residue (molar ratio) of 1-9, 0.2-1.0 dl/g reduced viscosity (ηsp/c ) and 35-70 deg.C glass transition temperature. Consequently, the objective antifouling coating material having high antifouling ability, extremely effective for fouling prevention for ship bottom parts, buoys, etc., due to low load on marine environment can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an antifouling paint composition and an antifouling paint using the same. In particular, it provides good results in the prevention of contamination by aquatic organisms such as microorganisms, algae and the like, which adhere to the surface of parts immersed in the sea or water, such as ships, marine structures, and various structures such as seawater introduction pipes. The present invention relates to an antifouling paint composition and an antifouling paint using the same.

[0002]

2. Description of the Related Art Ship bottoms, submarine communication cables, transportation pipelines, observation buoys, buoys, oil fences, piers, sluices, cooling water channels in thermal or nuclear power plants,
Industrial cooling water channels, wave power buoys, various equipment, facilities and structures related to marine development and marine civil engineering, for example, barnacles, mussels, oysters, hydro insects, moss insects, sea squirts, etc. Attached microorganisms that form slimes of algae such as blue-green algae, cyanobacteria, diatoms, and bacteria (hereinafter, collectively referred to as "fouling organisms") adhere thereto. Constructs and the like suffer various losses.

[0003] For example, when fouling organisms adhere to the bottom of a ship or the like, the frictional resistance between the hull and seawater increases, resulting in a decrease in ship speed,
This leads to an increase in fuel consumption. In addition, it causes economic loss such as suspension of operation due to fouling of the ship bottom and cleaning costs. Alternatively, in a structure constructed in the ocean, such as a bridge pier, the anticorrosion coating applied to enhance durability is deteriorated or corroded by fouling organisms, and as a result, the life of the structure is shortened. In addition, in the cooling water channels such as condensers of power plants and heat exchangers of various factories, fouling organisms adhere to them, thereby increasing the resistance during water intake, reducing heat exchange efficiency, Various losses occur, such as deterioration of the performance of condensers and heat exchangers caused by living organisms that have fallen off the ground.

[0004] As described above, the adhesion of fouling organisms to structures and the like existing in water causes extremely large damages in industry. For this reason, conventionally, in order to prevent fouling organisms from adhering,
Biological methods using natural enemies of living things that cause adhesion,
Use of structural materials that are difficult to adhere to (eg, coating the surface of structures with silicone-based paints and fluorine-based paints);
Prevent inflow of larvae of fouling organisms (for example, blocking with a screen, etc.), and exterminate larvae of fouling organisms (for example, use of light, ultraviolet rays, colors, ultrasonic waves, etc. and formation of environments that are difficult to survive due to heating, lack of oxygen, etc. ), Mechanical removal of fouling organisms (eg,
Cleaning, jet cleaning, brushing and suctioning, etc.) and chemical methods (eg, use of shell killers, repellents, antifouling agents, etc.) have been studied. Above all, the application area is wide and high effects are obtained, and the processing is easy.
A method of applying a paint containing a shellicide, a repellent, an antifouling agent, and the like has been widely adopted.

[0005]

However, in the case of paints containing chemicals such as shellfish, repellents and antifouling agents, the chemicals in the coating film gradually elute into water or the paints gradually disappear. It is a so-called self-polishing type paint designed to be scraped and dissipated into the water and always expose a new painted surface.
(Also called "marine environment").

Particularly in the 1980's, when contamination of fish and shellfish by a tin compound, which is the most typical component having an antifouling property (property of preventing the attachment of organisms), was pointed out, tin compounds in various European countries and the United States became popular. Antifouling paint containing (A paint that prevents fouling organisms from adhering to underwater structures and equipment)
In addition, various regulations have been added to the law, and an alternative method for preventing fouling organisms has emerged as an urgent issue. However, heavy metal compounds such as cuprous oxide and tetramethylthiuram disulfide and carbamic acid compounds which are mainly used as antifouling paints at present also have considerably high toxicity like tin compounds. In addition, because it is a persistent compound with accumulation properties,
There are concerns about adverse effects on the marine environment. Accordingly, there is a need for an antifouling paint that maintains excellent antifouling properties for a long period of time and does not adversely affect the marine environment.

[0007] An object of the present invention is to provide a good result in the prevention of fouling by fouling organisms adhering to the surface of parts submerged in the sea or water, such as ships, marine structures, various structures such as seawater inlet pipes, Another object of the present invention is to provide a composition for an antifouling paint having a small impact on the marine environment. Another object of the present invention is to provide an antifouling paint using the above antifouling paint composition.

[0008]

Means for Solving the Problems In view of these circumstances, the present inventors have made intensive studies, and as a result, a composition for an antifouling paint having a specific antifouling agent and a specific resin has achieved the above object. To complete the present invention.

That is, the present invention provides: (1) a resin containing a thiocyanic acid compound and a lactic acid residue in an amount of 90 mol% or more in a resin, wherein the L-lactic acid residue / D-lactic acid residue (molar ratio) in the lactic acid residue is 1 to 9; And the reduced viscosity (η _{sp / c} ) is 0.2 to
A composition for an antifouling paint containing 1.0 dl / g and a polyester resin having a glass transition temperature of 35 to 70 ° C. (2) L-lactic acid residue / D-lactic acid residue in lactic acid residue (molar ratio)
The composition for an antifouling paint according to the above (1), wherein (3) The antifouling paint composition according to the above (1), wherein the thiocyanic acid compound is methylenebisthiocyanate. (4) The antifouling paint composition according to the above (1), wherein the thiocyanate compound is 10 to 500 parts by weight based on 100 parts by weight of the polyester resin. (5) The antifouling paint composition according to (1), which is applied to a ship bottom, a sluice, a buoy, or a cooling water pipe of a power plant, and (6) the antifouling method according to any of (1) to (5). The present invention relates to an antifouling paint comprising a paint composition.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The thiocyanate compound, which is a component of the antifouling paint composition of the present invention, imparts good antifouling properties to invertebrates such as barnacles and poplars.
Examples of the thiocyanic acid compound include, but are not particularly limited to, methyl thiocyanate, methylene bisthiocyanate, ethylene dithiocyanate, and benzyl thiocyanate. Among them, methylene bisthiocyanate is preferred from the viewpoint of antifouling properties. One or more thiocyanic acid compounds can be used.

The antifouling paint composition of the present invention contains a polyester resin in addition to the thiocyanate compound. The polyester resin contains 90 mol% or more of lactic acid residues in the resin. When the content of the lactic acid residue is less than 90 mol%, physical properties such as the hardness of the coating film deteriorate. The polyester resin has biodegradability (a property that is susceptible to biochemical degradation).

In the lactic acid residue in the polyester resin,
The molar ratio (L / D) of L-lactic acid residue / D-lactic acid residue is 1 to 9, preferably 1 to 3. If the L / D exceeds 9, the solubility of the polyester resin in the solvent usually used for the antifouling paint will be insufficient, and it will be difficult to make the paint. Conversely, L
If the ratio / D is less than 1, the cost becomes high, which is not practical.

The polyester resin may contain a glycol residue, a caprolactone residue, a succinic acid residue and the like in addition to the lactic acid residue.

The reduced viscosity of the polyester resin is from 0.2 to
1.0 dl / g, preferably 0.3 to 0.8 dl
/ G. When the reduced viscosity of the resin is less than 0.2 dl / g, the coating film becomes brittle and the adhesion strength to the base coating film is reduced. On the other hand, if the reduced viscosity exceeds 1.0 dl / g, there arises a problem that coating suitability is deteriorated. Here, the measurement of the reduced viscosity is as follows:
This was performed by dissolving 125 mg of a polyester resin in 25 ml of chloroform and using an Ubbelohde viscosity tube at 25 ° C.

The glass transition temperature (T
g) is 35-70 ° C, preferably 40-70 ° C
It is. When Tg is less than 35 ° C., a tacky feeling remains when the coating film is dried, and sufficient coating film hardness required for applications such as ship bottoms, sluice gates, buoys, and cooling pipes of power plants can be obtained. However, polyester resins having a Tg exceeding 70 ° C. cannot be synthesized. Here, the measurement of the glass transition temperature was performed by differential thermal analysis.

The polyester resin is prepared by heating a dimer of lactic acid, such as lactide and glycolide, in a nitrogen atmosphere using a known ring-opening polymerization catalyst. It can be obtained by a method or the like. The polymerization method, catalyst and the like at this time are not particularly limited.

The components copolymerizable with the polyester resin include polybasic acids and polyhydric alcohols. Examples of the polybasic acid include aliphatic carboxylic acids and oxyacids, and examples of the polyhydric alcohol include glycol and the like. Examples of the aliphatic dicarboxylic acid include oxalic acid, succinic acid, and adipic acid, and examples of the oxy acid include glycolic acid, caprolactone, and malic acid. Examples of the glycol include ethylene glycol, propylene glycol, and butanediol.

The amount of the thiocyanate compound is preferably 10 to 50 parts by weight based on 100 parts by weight of the polyester resin.
0 parts by weight, more preferably 15 to 300 parts by weight. If the amount is less than 10 parts by weight, the antifouling property tends to be remarkably reduced, and if it exceeds 500 parts by weight, the properties of the coating film tend to be reduced.

The antifouling paint of the present invention is prepared by dissolving the antifouling paint composition in an organic solvent. Examples of usable organic solvents include ester solvents such as ethyl acetate and butyl acetate, aromatic solvents such as xylene, toluene and ethylbenzene, ketone solvents such as methyl ethyl ketone and cyclohexanone, and alcohol solvents such as isopropyl alcohol and butyl alcohol. And ether-based solvents such as tetrahydrofuran. The antifouling paint is a self-polishing antifouling paint capable of exhibiting antifouling properties over a long period of time because it contains a polyester resin having biodegradability.

The antifouling paint composition of the present invention may further contain additives usually added to the paint, for example, red iron oxide, titanium oxide,
Pigments such as talc and carbon, anti-sagging agents, leveling agents, anti-settling agents, anti-segregation agents, defoamers, waxes and the like can be added as necessary.

The solid content in the antifouling paint composition of the present invention is appropriately determined depending on the purpose of use, but is usually 30 to 80% by weight when applied to a ship bottom or the like.

The antifouling paint can be applied by any method, including, for example, coating and dipping.

The antifouling paint composition of the present invention has a long-lasting antifouling property because the polyester resin constituting the composition has biodegradability, and has no adverse effect on the marine environment. A membrane can be provided. That is, in a coating film formed from a paint containing a resin having no biodegradability, a component exhibiting antifouling properties is present on the surface immediately after application, but the component decreases over time. However, since the coating film itself does not decompose, the coating film that has passed the time can no longer exhibit antifouling properties. On the other hand, in the polyester resin used in the present invention, the resin forming the surface of the coating film gradually decomposes, so that the coating film containing the thiocyanate compound that always exhibits antifouling properties appears on the surface, The antifouling property can be continuously exhibited for a long time. In addition, the components that the coating film is decomposed and dissolved in water do not adversely affect the marine environment, such as thiocyanate compounds and lactic acid.

[0024]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited to the following examples.

Polymerization of polyester resin Production Example 1 1 kg of DL lactide, 4.46 g of calcium lactate as a polymerization initiator, 0.9 g of aluminum acetylacetonate as a ring-opening polymerization catalyst 4 equipped with a stirrer and a thermometer
The mixture was heated at 200 ° C. and stirred for 1 hour under a nitrogen atmosphere to polymerize the mixture.
Unreacted monomer is distilled off by reducing the pressure to Hg,
A polyester resin (A-1) was obtained.

Production Example 2 A polyester resin was prepared in the same manner as in Production Example 1, except that 1 kg of DL lactide, 50 g of glycolide, 1 g of glycolic acid as a polymerization initiator, and 0.9 g of aluminum acetylacetonate as a ring-opening polymerization catalyst were used. (A-2) was obtained.

Production Example 3 The same method as in Production Example 1 was used except that 900 g of L-lactide, 100 g of DL lactide, 5.4 g of decanol as a polymerization initiator, and 0.9 g of aluminum acetylacetonate as a ring-opening polymerization catalyst were used. Polyester resin (A-
3) was obtained.

Production Example 4 A polyester resin (A-4) was obtained in the same manner as in Production Example 1, except that 1 kg of DL lactide and 10 g of lactic acid were used as a polymerization initiator.

Production Example 5 A polyester resin (A-5) was obtained in the same manner as in Production Example 1, except that 1 kg of DL lactide and 0.1 g of lactic acid were used as a polymerization initiator.

Production Example 6 A polyester resin (A-6) was obtained in the same manner as in Production Example 1, except that 850 g of DL lactide, 150 g of caprolactone, and 1 g of glycolic acid were used as a polymerization initiator.

The compositions, reduced viscosities and properties of the resins obtained in Production Examples 1 to 6 are shown in Table 1. As shown in Table 1, A-
Sample No. 3 had an L / D of more than 9, and thus did not have solubility in xylene and could not be formed into a paint. Further, A-4 was too low in molecular weight, so that when it was formed into a coating, the coating film was brittle and was unsuitable for long-term evaluation of antifouling properties. A-5 had a too low molecular weight, and when formed into a paint, the paint viscosity was high and the coating suitability was poor. In the case of the paint using A-6, even if the coating film was dried, a tacky feeling remained, and it was unsuitable for uses such as a ship bottom, a water gate, a buoy, and a cooling pipe of a power plant.

[0032]

[Table 1]

Preparation of paint Example 1 29 g of polyester resin A-1 was dissolved in 40 g of xylene, and then 17 g of methylenebisthiocyanate, ₃ g of acetylated vitamin K ₃ , 10 g of red stalk and 1 g of colloidal silica were added and mixed. 1 was obtained. The mixing was performed using a homomixer at 2000 rpm.

Example 2 29 g of the polyester resin A-2 was dissolved in 40 g of xylene, and then 17 g of methylenebisthiocyanate, ₃ g of acetylated vitamin K ₃ , 10 g of red stalks and 1 g of colloidal silica were added and mixed to prepare the paint B-2. Obtained. The mixing was performed using a homomixer at 2000 rpm.

Comparative Example 1 19 g of an acrylic resin (composition: methyl methacrylate / styrene / ethyl acrylate / 2-hydroxyethyl acrylate = 50/10/30/10 (wt%)) was dissolved in 40 g of xylene and then 35 g of cuprous oxide. , 5 g of rosin and 1 g of colloidal silica were added and mixed to obtain paint B-3. The mixing was performed using a homomixer at 2000 rpm.

Comparative Example 2 44 g of an acrylic resin [composition: methyl methacrylate / styrene / ethyl acrylate / 2-hydroxyethyl acrylate = 50/10/30/10 (wt%)] was dissolved in 40 g of xylene, followed by 5 g of rosin and a valve. 10g pattern
And 1 g of colloidal silica were added and mixed to obtain Paint B-4. The mixing was performed using a homomixer at 2000 rpm.

Comparative Example 3 29 g of an acrylic resin [composition: methyl methacrylate / styrene / ethyl acrylate / 2-hydroxyethyl acrylate = 50/10/30/10 (wt%)] was dissolved in 40 g of xylene, and then 17 g of methylene bisthiocyanate. , Acetylated vitamin K ₃ 3g, red petal 10g
And 1 g of colloidal silica was added and mixed to obtain Paint B-5. The mixing was performed using a homomixer at 2000 rpm.

Table 2 shows the compositions of the paints obtained in Examples 1 and 2 and Comparative Examples 1 to 3.

[0039]

[Table 2]

Evaluation of antifouling performance Sandplast-treated steel sheet (50 mm × 100 mm × 1 m
m) A tar vinyl-based anticorrosive paint was previously applied to both sides and dried, followed by Examples 1-2 and Comparative Example 1
Each of the paints obtained in (1) to (3) has a dry film thickness of 10
It was spray-coated so as to have a thickness of 0 μm. After drying for 1 week in a constant temperature and humidity room at a temperature of 20 ° C and a humidity of 75%, each treated steel sheet was immersed in a water depth of 1.5m off the coast of Iwakuni, Yamaguchi Prefecture, and the state of biofouling after 3 and 6 months was observed. Then, antifouling performance evaluation was performed. Table 3 shows the results. The antifouling performance was evaluated by visual inspection based on the coverage of the coating film area with the attached organisms.

[0041]

[Table 3]

As is clear from Table 3, it was confirmed that Examples 1 and 2 had a high antifouling performance equal to or higher than Comparative Example 1. However, in Comparative Example 1, since the cuprous oxide and the acrylic resin were used, it is considered that the eluted material adversely affects the marine environment.

[0043]

The antifouling paint comprising the antifouling paint composition of the present invention has high antifouling performance and a small load on the marine environment of the antifouling agent as a component of the paint. Therefore, the present invention is extremely useful for preventing marine structures such as ship bottoms, buoys, sluice gates, and various water supply and drain pipes for cooling from being fouled by fouling organisms.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masaya Tokai 2-1-1 Katata, Otsu City, Shiga Prefecture Inside Toyobo Co., Ltd. Research Institute (72) Keiichi Uno 2-1-1 Katata, Otsu City, Shiga Prefecture No.Toyobo Jisho Co., Ltd. (72) Kenichi Akamine 3-1-1, Toyosu, Koto-ku, Tokyo Ishikawajima Harima Heavy Industries Co., Ltd. (72) Kumiko Kamada 3-1-1, Toyosu, Koto-ku, Tokyo 15 Ishikawajima Harima Heavy Industries, Ltd. (72) Inventor Yoichi Hirai 3-1-1-15 Toyosu, Koto-ku, Tokyo

Claims (6)

[Claims] 1. A resin comprising a thiocyanic acid compound and a lactic acid residue in an amount of 90 mol% or more in a resin, wherein L-lactic acid residue / D-lactic acid residue (molar ratio) in the lactic acid residue is 1 to 9; _{sp / c} ) is 0.2 to 1.0 dl / g, and the glass transition temperature is 35 to 70.
A composition for an antifouling paint containing a polyester resin having a temperature of ° C. 2. The antifouling paint composition according to claim 1, wherein the ratio of L-lactic acid residue / D-lactic acid residue (molar ratio) in the lactic acid residue is 1 to 3. 3. The antifouling paint composition according to claim 1, wherein the thiocyanic acid compound is methylene bisthiocyanate. 4. 100 parts by weight of a polyester resin,
The antifouling paint composition according to claim 1, wherein the thiocyanate compound is present in an amount of 10 to 500 parts by weight. 5. The antifouling paint composition according to claim 1, which is applied to a ship bottom, a floodgate, a buoy, or a cooling water pipe of a power plant. 6. An antifouling paint comprising the antifouling paint composition according to claim 1.