JPH051246A - Antifouling coating composition - Google Patents

Abstract

PURPOSE:To provide an antifouling coating composition which can show a stable antifouling effect for a long time and is suitable for use especially in sea water. CONSTITUTION:An acetoacetylated polymer comprising, in the form of the final copolymer, an acetoacetylated monomer and a monomer copolymerizable therewith is used as a vehicle component. This component is mixed with an inorganic copper compound and/or copper and thiabendazole.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a so-called antifouling paint which prevents marine organisms such as shellfish and seaweeds from adhering in the sea.

[0002]

2. Description of the Related Art Preventing marine organisms from adhering to ship bottoms or undersea structures is extremely important for efficient operation and maintenance of these. As a countermeasure for this, a paint containing organic tin has been conventionally used as an effective one. However, in recent years, accumulation of organotin compounds mainly in fish has come to be a problem, and it tends to be difficult to use them as an antifouling agent from the viewpoint of public health. On the other hand, in place of these organotin-based paints, the use of inorganic copper compounds centered on cuprous oxide, which has no accumulation property in fish and has been used for a long time, has been receiving attention again.

However, as is well known in the art, a so-called "eel paint" function, in which a polymer such as triphenyltin methacrylate, flows out from the surface in a very small amount in water, for example, is typical. It is said that it is difficult for a coating composition containing cuprous oxide, which is an inorganic copper compound, as an antifouling agent to have.

A paint containing cuprous oxide as an antifouling agent and rosin as a vehicle is not easily a paint having a long-term antifouling effect due to severe wear in seawater, and a chlorinated rubber vehicle was used. It is said that antifouling paints also lose their antifouling effect if the cuprous oxide distributed on the surface is eluted.

In order for a coating film containing cuprous oxide to exhibit an antifouling effect, it is said that 8 to 11 μg / cm ² / day of copper zinc oxide must be eluted, and this value is constant over a long period of time. Keeping the value is essential for a stable antifouling paint.

[0006] Thus, numerous studies have been carried out in order to obtain a vehicle for coatings which contains the required amount of cuprous oxide and whose surface coating is constantly renewed so as to provide a sufficient amount of cuprous oxide. ing.

[0007] Among them, there are examples in which a monomer forming a water-soluble polymer, for example, vinylpyrrolidone is used as one component of a copolymer, or a monomer having a tertiary amino group is used.

However, the existing antifouling paints using these polymers as vehicles do not show changes in physical properties depending on the use environment, that is, the solubility of the polymers does not change with time.

The desired trend is that of the "eel paint" trend mentioned above, ie that the surface polymer is constantly updated so as to be able to supply a constant quantity of cuprous oxide while containing it.

The present inventors have conducted studies on a vehicle which uses an inorganic copper compound such as cuprous oxide as an antifouling agent and can release a sufficient amount of copper ions to exhibit an antifouling effect for a long period of time. The inventors have found that the object can be achieved by using a polymer having an acetoacetyl group as at least one component, and have previously filed an application (JP-A-3-
No. 126771).

However, when an inorganic copper compound such as cuprous oxide is used as the antifouling agent, the antifouling action has not always been satisfactory.

[0012]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the problems of the prior art and to provide an antifouling coating composition for preventing the adhesion of marine organisms.

[0013]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to solve the above-mentioned problems, and as a result, have proposed the antifouling coating composition proposed by the present inventors and applied for a patent (Japanese Patent Application Laid-Open No. Hei 3 (1999) -311). -12
It was found that the addition of thiabendazole to JP 6771) can provide an antifouling coating composition exhibiting a stable antifouling effect for a longer period of time, and arrived at the present invention.

That is, according to the present invention, [A] the final copolymer is in the form of (1) a monomer having an acetoacetyl group and (2) at least one monomer copolymerizable therewith. The present invention relates to an antifouling coating composition comprising a polymer having an acetoacetyl group in a form obtained by polymerization, [B] an inorganic copper compound and / or copper, and [C] thiabendazole.

The form of the final copolymer to be used as a vehicle component in the present invention is a polymer having an acetoacetyl group, (1) a copolymer of a monomer having an acetoacetyl group and a monomer copolymerizable therewith. Alternatively, (2) a polymer having a hydroxyl group can be reacted with diketene.

A typical example of the above methods (1) and (2) is as follows.

Method (1)

[Chemical 1]

Method (2)

[Chemical 2]

The polymer having an acetoacetyl group can be synthesized as a homopolymer or a copolymer with a copolymerizable monomer.

As is well known, the acetoacetyl group has a typical keto-enol tautomerism.

[0021]

[Chemical 3] It is considered that the homopolymerization of a monomer having an acetoacetyl group may be related to the above-mentioned keto-enol tautomerism, but it rapidly becomes a gel as the polymerization rate increases. It was difficult to obtain a stable polymer unless a large amount of the agent was used.

However, it has been clarified that this drawback can be alleviated by copolymerizing a monomer having an acetoacetyl group and a copolymerizable monomer.

Further, a polymer having an acetoacetyl group obtained by copolymerizing a monomer having an acetoacetyl group and a monomer copolymerizable with the acetoacetyl group has an elution rate when an antifouling agent such as cuprous oxide is also used. I also found that I could control it.

Suitable examples of the acetoacetyl group-containing monomer for obtaining the acetoacetyl group-containing polymer used in the method (1) of the present invention include the following reaction products of unsaturated alcohols and diketene. Be done.

2-hydroxyethyl acrylate, 2-
Hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, polyethylene glycol monomethacrylate, allyl alcohol and the like.

Primary alcohols are easier to react with diketene and are sufficient for the present invention.

The monomer copolymerizable with the monomer having an acetoacetyl group is not particularly limited, and various types of water-insoluble monomers and water-soluble monomers can be used.

That is, when a large amount of water-soluble monomer is used, the initial elution of copper ions is rapid, but the change over time is also large, and the ion concentration required for the desired number of days tends not to be maintained. Yes, utilization of water insoluble monomers shows the opposite trend. Therefore, if a monomer having an acetoacetyl group is the main component, the amount of the water-soluble monomer is controlled, and if necessary, a water-insoluble monomer is added as the third component, desired copper ion release can be expected for a long period of time. Like

Examples of the monomer copolymerizable with the monomer having such an acetoacetyl group include styrene, vinyltoluene, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate and methacrylic acid. t-Butyl, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, benzyl methacrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, acrylonitrile, methacrylonitrile, vinyl acetate, vinyl propionate, vinyl chloride, vinylpyrrolidone. , Acrylic acid, methacrylic acid, methylol acrylamide, acrylamide, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate DOO, 2-hydroxypropyl methacrylate, and quaternary ammonium salt-forming monomers, typically adduct of dimethylaminoethyl methacrylate and benzyl chloride is an unsaturated tertiary amine.

The proportion of the monomer having an acetoacetyl group and the monomer copolymerizable therewith is preferably 99 mol% or less and 20 mol% or more of the monomer having an acetoacetyl group. If the proportion of the monomer having an acetoacetyl group is more than 99 mol%, it is difficult to obtain a stable polymer, and if it is less than 20 mol%, if the monomer used in combination is water-insoluble, the outflow rate of copper ions is It becomes late and it is difficult to obtain the desired antifouling effect. A more suitable ratio is 95 mol% or less and 50 mol% or more.

For polymerization, usual methods are applied, but the proportion of the monomer having an acetoacetyl group is 50 mol%.
In the above cases, it is appropriate to use a chain transfer agent, typically a mercaptan, in an amount of 1% by weight or more in order to avoid an increase in viscosity at the end of polymerization as described above.

A polymer having an acetoacetyl group can also be obtained by reacting a polymer having a hydroxyl group with diketene as in the above method (2).

As the polymer having a hydroxyl group used in the method (2) of the present invention, in addition to the copolymer obtained by copolymerizing a monomer having a hydroxyl group and another monomer, for example, ethylene and vinyl acetate. Examples thereof include saponified copolymers, acetal, formal, and butyralized polymers thereof.

Preferred examples of the monomer having a hydroxyl group include the unsaturated alcohols described in the above method (1). Also, as for the other monomers, the above-mentioned copolymerizable monomers are also mentioned.

The reaction between the polymer having a hydroxyl group and diketene is carried out in a closed container at a temperature of about 60 ° C. in the presence of a catalyst such as an organic tin compound and a tertiary amine.

In the present invention, the antifouling agent used in combination with the polymer having an acetoacetyl group is an inorganic copper compound and / or copper and thiabendazole.

As the most typical inorganic copper compound, cuprous oxide can be cited, and in addition, for example, basic copper carbonate, basic copper sulfate, basic copper phosphate, copper carbonate, copper hydroxide, Copper silicate etc. can be mentioned. Examples of copper include copper powder.

The amount of the inorganic copper compound and / or copper used is generally 50 to 200 parts by weight based on 100 parts by weight of the polymer having an acetoacetyl group, which is a vehicle component. Can be increased or decreased by.

In the present invention, an inorganic copper compound and /
Alternatively, the antifouling effect is dramatically improved by further adding thiabendazole to the copper antifouling agent.

Thiabendazole has the following structural formula

[0041]

[Chemical 4] It is represented by [4- (2-benzimidazoyl) thiazole] and is useful mainly as a food additive for preventing spoilage of citrus fruits.

The proportion of thiabendazole used is 1 part by weight or more and 50 parts by weight or less, preferably 5 parts by weight or more and 30 parts by weight or less, based on 100 parts by weight of the polymer having an acetoacetyl group. If the use ratio of thiabendazole is less than 1 part by weight, the effect of addition is poor, and it is difficult to improve the performance even if it is added in excess of 50 parts by weight.

There is no particular limitation on the method for preparing the antifouling coating composition of the present invention from these components, for example, toluene,
An antifouling paint is prepared by dissolving and adjusting a polymer having an acetoacetyl group such as methyl ethyl ketone so as to have an appropriate viscosity.

It is needless to say that the antifouling coating composition of the present invention may optionally contain a filler, a colorant, a polymer, an oligomer, an inorganic copper compound and / or an antifouling agent other than copper and thiabendazole.

[0045]

In the present invention, it is not always clear why the combined use of a polymer having an acetoacetyl group with, for example, cuprous oxide or thiabendazole can release a certain amount of copper ions. The formation of chelate bonds with compounds, the regeneration of hydroxyl groups by promoting hydrolysis of acetoacetyl groups in alkaline aqueous solution, and the accompanying increase in water solubility of polymers have some relation. It is also speculated.

[0046]

EXAMPLES Examples will be shown below to facilitate understanding of the present invention. In addition, the part in an Example is a weight part unless there is particular notice.

Example 1 Copolymer (A) (2-acetoacetylethyl meta
(Crylate-styrene) synthesis stirrer, reflux condenser, thermometer, in a 1-liter separable flask equipped with a gas introduction tube, 340 g of 2-acetoacetylethyl methacrylate, 40 g of styrene, 320 g of methyl ethyl ketone, 320 g of azobisisobutyronitrile 2
g and lauryl mercaptan 3.8 g were charged and polymerized at 65 to 70 ° C. for 8 hours in a nitrogen gas stream. During this period, 0.7 g of azobisisobutyronitrile was added every 2 hours. The polymerization rate was about 92%. Number average molecular weight 5400
As a result, a copolymerization polymer (A) (methyl ethyl ketone solution) having 2-acetoacetylethyl methacrylate (80 mol%) of 0 and styrene (20 mol%) having an acetoacetyl group was obtained. The color of the solution was slightly yellow and the viscosity was about 90 poise.

Preparation of Antifouling Paint [I] An antifouling paint [I] was prepared by thoroughly kneading 100 parts of the copolymer (A), 30 parts of methyl ethyl ketone and 110 parts of cuprous oxide. This kneaded product is about 2 in a closed container.
It could be painted for a day.

Production of antifouling paint [II] 100 parts of copolymer (A), 110 parts of cuprous oxide,
50 parts of methyl ethyl ketone and 20 parts of thiabendazole were kneaded to produce an antifouling paint [II].

Antifouling paint [I] and antifouling paint [II] were applied and dried to a dry coating film thickness of about 70 to 100 μm on a bonderite steel plate whose back surface was anticorrosion coated with an epoxy resin. The coating films formed from the antifouling paint [I] and the antifouling paint [II] each had a pencil hardness of 2H and a goggles adhesion test of 100/100.

Copper Ion Elution Test For each of the coated samples above, the Rechem (R
The leaching test of copper ion elution was performed according to the method using the glycine solution of E. That is, glycine 1.785 g sodium chloride 27.960 g 0.1% caustic soda 28.8 cc distilled water 1000 cc A solution having a pH adjusted to 10.5 was used.

The acceleration factor is usually said to be 20 to 30 times, but here it was calculated as 20 times. Initial test start 3
The amount of copper ions eluted per day (corresponding to 60 days) was 94 μg / cm ² / day for antifouling paint [I] and 79 μg for antifouling paint [II].
g / cm ² / day, 360 days equivalent, antifouling paint [I] 41
μg / cm ² / day, antifouling paint [II] 38 μg / cm ² /
Sun, equivalent to 720 days, antifouling paint [I] is 39-41μ
g / cm ² / day, antifouling paint [II] 40-41 μg / cm ²
/ Day, both coated samples showed sufficient copper ion elution.

A slate plate having a thickness of 6 mm, cut into 30 cm × 20 cm, is attached to “Spray Dam # 50” manufactured by Showa High Polymer Co., Ltd.
After spray coating 0 "to a thickness of about 2 mm to form a cured coating film, the antifouling coating materials [I] and [II] are applied to a coating film thickness of 70 to 70 mm, respectively.
It was coated and dried three times so as to have a thickness of 100 μm.

The above-mentioned coated slate board and unpainted slate board were immersed in the same place 1 m below sea level for 10 months from February to November, and the antifouling paint [I] was applied to the slate board. About 15 to 20% of the total area of algae like blue seaweed and two barnacles were attached to the plate. The slate plate coated with the antifouling paint [II] had almost no algae attached, and no adhesion of shellfish was observed. On the other hand, on the unpainted slate board, there was a large amount of shellfish adhered so that the base could not be seen completely.

Example 2 Synthesis of Copolymer (B) In a 1 liter separable flask equipped with a stirrer, a reflux condenser, a gas introduction tube, and a thermometer, 240 g of 2-acetoacetylethyl acrylate, 55 g of butyl acrylate,
Acrylonitrile (10 g), toluene (295 g), t-butyllauryl mercaptan (2 g) and azobisisobutyronitrile (3 g) were charged, and the mixture was polymerized in a nitrogen stream at 70 to 75 ° C. for 16 hours. 1.5 g of azobisisobutyronitrile was added every 4 hours and 8 hours on the way. Polymerization rate is about 93%
And a copolymer (B) (toluene solution) having an acetoacetyl group having a number average molecular weight of 64,000 was obtained. The solution was pale yellow and had a viscosity of about 40 poise.

Production of antifouling paint [III] Basic copper carbonate 5 to 100 parts of copolymer (B)
0 part, 50 parts of copper powder, and 50 parts of cuprous oxide were kneaded to obtain a paste-like antifouling paint [III].

Production of Antifouling Paint [IV] An antifouling paint [IV] was prepared by further mixing 30 parts of methyl ethyl ketone and 15 parts of thiabendazole with the antifouling paint [III] (the above-mentioned compounding amount).

The above antifouling paints [III] and [IV] were separately coated on a bonderite steel plate treated in the same manner as in Example 1 in three times so as to have a dry film thickness of 70 to 100 .mu. It was a film.

The surface of the coating film was non-adhesive in all cases, and the pencil hardness was F and the eyelet adhesion test was 100/100. As a result of conducting the accelerated test in the same manner as in Example 1, in each case the first 3
Day between Although there is variation and 59μg / cm ² / day ~91μg / cm ² / day, 360 days corresponds with 39～42Myug /
cm ² / day, 24 to 30 μg / cm ² / day corresponding to 720 days.

Using each of the antifouling paints [III] and [IV], a coating slate plate was prepared in the same manner as in Example 1 and immersed in the same place 1 m below sea level for 10 months from February to November. Then, the immersion test was performed. On the slate plate coated with the antifouling paint [III], blue seaweed-like seaweed adhered to the area of about 20 (%), but no shellfish adhered. Almost no algae adhered to the slate board coated with the antifouling paint [IV], and no shellfish adhered.

[0061]

EFFECTS OF THE INVENTION Since the antifouling coating composition of the present invention is constructed as described above, it has a long pot life and is excellent in coatability on a substrate. By the action, the elution rate of copper ions can be made constant, so that a long-term antifouling coating film performance can be obtained.Vessel bottoms, fishing nets, underwater structures, various instruments that are immersed in the sea for a long time, etc. It is extremely useful as an antifouling paint for preventing the attachment of marine organisms such as those described above that require the prevention of the attachment of marine organisms.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location C09D 201/06 PDM 6770-4J

Claims (1)

Claims: 1. [A] The final form of the copolymer is (1) a monomer having an acetoacetyl group,
(2) A polymer having an acetoacetyl group in a form obtained by copolymerizing this with at least one kind of a copolymerizable monomer, [B] an inorganic copper compound and / or copper, and [C] thiabendazole An antifouling coating composition which is used in combination with.