JP2651499B2 - Resin composition for antifouling paint - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to a novel resin composition for an antifouling paint for marine structures.

In more detail, since the coating film is strong and has a suitable water solubility, and the resin itself releases a metal compound as an antifouling agent into the sea by hydrolysis, it is necessary to reduce the amount of antifouling agent to be incorporated into the paint. The present invention relates to a resin composition for seawater antifouling paints that can be used and has a long-term antifouling property and is used for ship bottoms and underwater structures.

(Prior Art) The surface of an object under water is usually covered with a multi-layer paint film, and is usually protected as a top coat to prevent the growth of living organisms such as algae and barnacles living in the sea. Dirty paint is applied.

By the way, such antifouling paints contain antifouling agents such as cuprous oxide, which itself is a poison, which gradually reacts with seawater to grow water-soluble salts. It is sequentially eluted from the paint film in the form of

However, in the dissolution process of these antifouling agents, it is difficult to control the dissolution rate to be uniform,
In addition, the dissolution occurs undesirably quickly as soon as the ship to which the antifouling paint has been applied enters service or begins to re-enter, resulting in an unnecessarily high concentration of toxic antifouling agent. Around the seawater, which results in waste of the antifouling agent and neglect of water contamination, and after a certain degree of elution, the concentration of the antifouling agent decreases, resulting in inhabiting in the sea. The growth of the organism will be enhanced.

As a conclusion of these facts, development of a resin that can be artificially controlled so that the dissolution rate of the antifouling agent becomes uniform is expected.

Copolymers having tributyltin oxide as a side chain as a substance capable of making the dissolution rate of this kind of antifouling agent uniform to some extent and suppressing the growth or promotion of the marine organism for a relatively long period of time, for example. There is. However, since this copolymer produces tributyltin oxide by hydrolysis, this causes seawater pollution and seriously affects fish and shellfish.

In addition, carboxyl groups with excellent hydrolyzability,
Although a (co) polymer having a functional group such as a dimethylamino group or a hydroxyl group in a side chain is used, even when these (co) polymers are used, all of them are uniform over a long period of time. If the carboxyl group- and hydroxyl group-containing copolymer is used in a paint using a metal-based antifouling agent such as cuprous oxide, the stability of the paint becomes extremely poor. The point is revealed. In addition, although rosin-based resins have been used for a long time as a resin component of this type of top coat, they have a drawback that they lack long-term antifouling properties.

The present inventor has provided a coating resin composition which has a carboxylate blocked with a trialkylsiloxy group on the side chain of a vinyl copolymer and has excellent hydrolyzability and gives a self-polishing coating film. . (Japanese Patent Application No. 62-4978
No. 35). Such a resin is hydrolyzed under alkaline conditions such as seawater and solubilized together with an antifouling agent in the form of a sodium carboxylate.However, from the viewpoint of long-term use and public health, the amount of the antifouling agent used is as small as possible. When evaluated from the viewpoint of reducing the number, there is still room for improvement.

(Problems to be Solved by the Invention) Therefore, a main object of the present invention is to provide a resin having a group capable of generating a hydrophilic group by hydrolysis in a side chain portion thereof, and to undergo moderate hydrolysis in seawater. Provides a novel resin composition for antifouling paints that is based on a resin with excellent film forming properties that elutes and elutes, and does not depend on tributyltin salt, which is expensive and its use is considered undesirable from the viewpoint of seawater contamination Is to do.

[Configuration of the invention]

(Means for Solving the Problems) To summarize the present invention, the present invention provides: (i) main components are methyl vinyl ether, N-vinylpyrrolidone, methoxyethylene glycol methacrylate,
In addition, water-soluble copolymers composed of monomers selected from acrylamide or a slightly soluble resin such as rosin are used.
1 to 30% by weight, (ii) as a slightly hydrolyzable resin ● General formula 5-30 parts ● vinyl acetate and / or C ₁ -C ₂ lower alkyl (meth)
Acrylate: A resin composition for an antifouling paint which is obtained by mixing 70 to 99.9% by weight of a copolymer composed of 40 to 90 parts, and which has particularly excellent long-term antifouling properties.

 Hereinafter, the configuration of the present invention will be described in detail.

The water-soluble resin (co) polymer constituting the resin composition for an antifouling paint of the present invention is composed of a monomer containing methylbityl ether, N-vinylpyrrolidone, methoxyethylene glycol methacrylate or acrylamide as a main component. (Co) polymer.

Examples of those which exhibit good water solubility when copolymerized with methyl vinyl ether include enyl vinyl ether and vinyl acetate. Examples of those exhibiting good water solubility by copolymerizing with N-vinylpyrrolidone include lower (meth) acrylates such as vinyl acetate and methyl (meth) acrylate. Methoxyethylene glycol methacrylate,
Even when acrylamide is copolymerized with a lower (meth) acrylate, vinyl acetate or the like at 30% by weight or less, a copolymer having good water solubility can be obtained. The main component in the present invention means a copolymerization amount necessary for exhibiting water solubility.

The rosin used in the present invention is a rosin having an acid value of 120 or more and a melting point of 40 ° C. or more, gum rosin produced from pine tar, wood rosin extracted from pine roots and stumps, or kraft pulp. Since it contains tall oil rosin separated from by-product tall oil, it is slightly soluble.

The mixing ratio of the water-soluble resin or the slightly soluble resin to the water-insoluble resin is, for example, polymethyl vinyl ether or poly-methyl vinyl ether.
In the case of a water-soluble resin such as N-vinylpyrrolidone, poly (methoxyethylene glycol methacrylate), or polyacrylamide, the amount is 0.1 to 30 parts by weight, preferably 2 to 15 parts by weight, and in the case of a slightly soluble resin such as rosin, 20 to 30 parts by weight. 30 parts by weight.

If the amount used exceeds 50 parts by weight, the initial dissolution rate of the antifouling agent is too high, and it is impossible to uniformly reduce the coating film over a long period of time. Further, the water resistance of the coating film is extremely reduced. When the amount is less than 0.1 part by weight, the dissolution rate is low over the initial and long term, and after about three months, there is almost no dissolution of the antifouling agent, and the antifouling effect is extremely reduced.

The water-insoluble resin having a hydrolyzability, which is another important resin component of the present invention, is gradually hydrolyzed in an alkaline PH region together with the elution of the water-soluble resin and the slightly soluble resin described above in seawater, and is thus stain-resistant. Elutes in seawater with the agent. In this elution process, a new coating film surface is formed in order, that is, a so-called self-polishing coating film is formed.

In the composition of the slightly hydrolyzable resin having a role of controlling the dissolution rate in seawater used in the present invention, the most important component is a monomer represented by the general formula [I], [II] or [III]. The resin containing these monomer components is hydrolyzed in an alkaline pH range to produce an organic acid salt such as copper and a carboxylic acid.

The monomers represented by the above [I], [II], and [III] are:
For example, (i) an unsaturated organic acid such as (meth) acrylic acid or a vinyl carboxylic acid, (ii) an oxide or hydroxide of a metal having a lower ionization tendency than an alkali metal such as copper, zinc, and tellurium, and (Iii) It can be synthesized by a three-part esterification reaction of a monovalent organic acid.
(Hereinafter, the monomers represented by [I], [II], and [III] are referred to as metal-containing unsaturated monomers.) As the (i) unsaturated organic acid, methacrylic acid, acrylic acid, crotonic acid , Itaconic acid, maleic acid or fumaric acid; monoalkyl maleate (C ₁ -C ₄ ) ester, monoalkyl fumarate (C ₁ -C ₄ ) ester, or monoalkyl itaconate (C ₁ -C ₄ ) ester; Or β-hydroxyethyl (meth) acrylate, β-hydroxypropyl (meth) acrylate, β-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and β-hydroxyethyl (meth) acrylate with ε-caprolactone Those added [for example, Praxel FM, FA series (Daicel Corporation)
") Or" Blemmer PE "series represented by polyethylene glycol monomethacrylate (manufactured by NOF Corporation) or" Blemmer PP "represented by polypropylene glycol monomethacrylate
(Nippon Oil & Fats Co., Ltd.) series and a commonly used hydroxyl group-containing vinyl monomer and succinic anhydride as an anhydride of R ₅ ;
Typical examples include adducts with known and common acid anhydrides such as phthalic anhydride. (Ii) Examples of metal species of metal oxides or hydroxides include Cu, Zn, Te, and periodic II _b group table, III _a
Family, IV _a group (e.g. Sn, Pb, Si), VI a group (e.g., S
e), VI _b group (eg Cr, Mo), VII group (eg Mn), VI
Group II (for example, Fe, Co, Ni) may be used. Cu, Z
n and Te are preferable metal components. In short, a metal having a lower ionization tendency than an alkali metal is used. These metal components are used to minimize the use of conventional Sn-based toxic antifouling agents and the like, and to increase the effect.

The (iii) monovalent organic acids include acetic acid, propionic acid, benzoic acid, salicylic acid, lactic acid, 3,5-dichlorobenzoic acid, lauric acid, nitrobenzoic acid stearate, linoleic acid, ricinoleic acid, 1,2 -Hydroxystearic acid, parvic acid, abietic acid, naphthenic acid, chloroacetic acid, dichloroacetic acid, valeric acid, p-phenylbenzoic acid and the like.

The copolymer of the metal-containing unsaturated monomer represented by the above [I], [II] or [III] is 5 to 30 parts, preferably 5 to 20 parts.
Department. When the amount exceeds 30 parts, the amount of the copolymerized side chain organometallic ester becomes too large and is quickly hydrolyzed in an alkaline region, so that the long-term antifouling property cannot be maintained. In addition, the polymerization rate is hardly increased due to the remaining trace metal compound at the time of monomer synthesis. If it is less than 5 parts, the result will be inferior to the self-polysyncrin property.

In the present invention, the next important component after the above-mentioned metal-containing unsaturated monomer is a compound represented by the above general formula [IV]. Specific examples thereof include acrylamide, methacrylamide, N-methylacrylamide, N-ethylacrylamide, N-propylacrylamide, N-isopropylacrylamide, N, N-dimethylacrylamide, N, N'-diethylacrylamide, N, N- Dipropylacrylamide, N, N-diisopropylacrylamide, N-acetylacrylamide, N-methylmethacrylamide, N-ethylmethacrylamide, N-propylmethacrylamide, N-isopropylmethacrylamide, N, N-dimethylmethacrylamide, N, N-dipropyl methacrylamide, N-acetyl methacrylamide and the like.

The homopolymer of the monomer described as a specific example of the compound represented by the general formula [IV] is water-soluble, but becomes insoluble when 5 to 30 parts of the monomer is used in the present invention. . When the amount is less than 5 parts by weight, uniform elution of the coating film over a long period of time is not recognized, so that stable antifouling property cannot be maintained. When the amount is more than 30 parts, the initial degree of consumption (elution rate) is large, but the antifouling property cannot be maintained for a long time, and the water resistance of the coating film is extremely reduced.

In the present invention, an important monomer component next to the monomer components described in the above [I] to [IV] is vinyl acetate, and / or
Or methyl and ethyl methacrylates and acrylates. That is, these monomer components are necessary for forming a water-resistant and strong film of the coating film in seawater. It becomes a C ₃ or more (meth) acrylate increases the hydrophobicity of the coating film, it means that alienating hydrolysis of other components is not preferred.

From the various monomers constituting the antifouling paint resin composition of the present invention described above, a water-soluble resin, a polymerization method for obtaining a slightly hydrolyzable resin includes solution polymerization in the presence of a radical polymerization catalyst. Although it is convenient to carry out, suspension, bulk, ionic polymerization, photopolymerization, and radiation polymerization can also be used. The average molecular weight of the copolymer can be used from 5,000 to 80,000,
It is preferably from 7,000 to 30,000.

The antifouling paint resin composition of the present invention is blended with known and commonly used antifouling agents and pigments.

Among them, typical examples include anti-fouling agents such as zinc suboxide, zinc chromate, strontium chromate,
Cupric chromate, cupric citrate, cupric ferrocyanate, cupric quinoline, cupric δ-hydroquinoline, cupric oleate, cupric nitrate, cupric phosphate, tartaric acid Copper (II) cuprous oxide, cuprous oxide, cuprous iodide, cuprous sulfite, etc., and use of an organic tin compound, a triazine compound, an organic sulfur compound, or the like in combination with an antifouling agent does not impede. .

In the antifouling paint resin composition of the present invention, other,
It is needless to say that commonly used coloring pigments, extenders, organic solvents and the like can be freely selected and used.

The resin composition for antifouling paint of the present invention thus obtained is
Used as ship bottom paint or fishing net paint.

〔Example〕

Next, the present invention by reference examples, examples and comparative examples,
Although described more specifically, the present invention is not limited to these examples. In the following, all parts and percentages are by weight unless otherwise specified.

Reference Example-1 [Preparation Example of Methyl Vinyl Ether Copolymer] 800 parts of previously dehydrated xylene was charged into an autoclave equipped with a stirrer, a monomer injection line, and a catalyst injection line, and then heated to 700 ° C., followed by methyl addition. 900 parts of vinyl ether, 100 parts of ethyl bityl ether,
10 parts of boron trifluoride diethyl etherate were injected over 4 hours. After completion of the injection, the reaction was continued at 70 ° C. for 5 hours to obtain a resin solution having a nonvolatile content of 50.7% and a viscosity of OP (Gardner viscosity). Hereinafter, this is referred to as (a-1).

Reference Example-2 [Preparation of N-vinylpyrrolidone copolymer] 400 parts of xylene, n-butanol and 400 parts were charged into a four-necked flask equipped with a thermometer, a reflux condenser, a stirrer, and a nitrogen gas inlet. it then, after 30 minutes blowing N ₂ in the liquid, the temperature was raised to 100 ° C., 100 parts of xylene, 100 parts of n- butanol, Tashiya butyl peroxide octoate (TBPO) 1
After 0 parts, 80 parts of N-vinylpyrrolidone and 200 parts of methyl methacrylate were added dropwise over 5 hours, the reaction was further continued at 100 ° C. for 10 hours to obtain a resin solution having a nonvolatile portion of 50.4% and a viscosity of UV. Hereinafter, this is referred to as (a-2).

Reference Example-3 [Preparation example of methoxyethylene glycol methacrylate-based copolymer] In the same apparatus as Reference Example-2, 600 parts of n-butanol were added.
After charging 200 parts of xylene, the temperature was raised to 100 ° C., 200 parts of xylene, 8 parts of TBPO, 2 parts of ditertiary butyl peroxide, methoxyethylene glycol methacrylate 400
And 100 parts of methyl methacrylate were added dropwise over 4 hours, and the reaction was further continued at 100 ° C. for 8 hours to obtain a resin solution having a nonvolatile content of 50.2% and a viscosity of XY. Hereinafter, this is referred to as (a-3).

Reference Example-4 [Preparation Example of Acrylamide-Based Copolymer] In the same apparatus as Reference Example-2, 1000 parts of n-butanol were added.
Acrylamide 850 parts, methyl methacrylate 150 parts, TB
After charging PO20 part, gradually raise the temperature to 100 ° C,
After the reaction for 8 hours, 2 parts of TBPO was added and the reaction was continued. After 6 hours, a transparent resin solution having a nonvolatile content of 50.1% and a viscosity of Z was obtained.
Hereinafter, this is referred to as (a-4).

Reference Example-5 [Preparation Example 1 of slightly hydrolyzable resin] In the same apparatus as Reference Example-2, 300 parts of n-butanol were added.
After charging 300 parts of toluene, the temperature was raised to 105 ° C,
A monomer composition shown in Table 1, that is, a mixture of 100 parts of stearyl copper methacrylate, 20 parts of N, N-dimethylacrylamide, 400 parts of methyl acrylate, 300 parts of methyl methacrylate, 400 parts of butyl cellosolve, and 15 parts of TBPO was dropped in 3 hours. . Continue the reaction at 105 ° C and add 4 parts of TBPO every 4 hours.
The reaction was completed in 20 hours with additional
% To obtain a blue resin solution viscosity of Z _2. Hereinafter, this is referred to as (b-1).

Reference Example-6 [Preparation Example-2 of Slightly Hydrolyzable Resin] to Reference Example-11 [Preparation Example-7 of Slightly Hydrolyzable Resin] Table 1 shows the same apparatus and operation as in Reference Example-6. A slightly hydrolyzable resin solution having a monomer composition was obtained. Hereinafter, the prepared resin solutions are referred to as (b-2) to (b-7), respectively.

Reference Examples -12 to 13 [Examples of preparation of slightly hydrolyzable resin] By the same apparatus and operation as in Reference Example-6, a slightly hydrolyzable resin solution was obtained with the monomer composition shown in Table 1. . Hereinafter, these are referred to as (b-8) and (b-9).

[Preparation of Painted Test Plate] The antifouling paints of Examples 1 to 7 and the antifouling paints of Comparative Controls 1 to 4 were prepared based on the compositions shown in Table 2, and their performance was compared and examined according to the procedures described later. Was performed.

<Performance test procedure> [I] Rotary test An etching primer was applied once on a sandblasted 10 cm x 10 cm x 0.8 cm copper plate to a coating thickness of 5 µm, and a tar vinyl-based ship bottom rust preventive paint was applied once to a coating thickness of 70 µm. Painted.

Next, each of the antifouling paints of Example 1-7 and Comparative Example 1-4 was applied three times with a coating thickness of 60 μm, and each of the obtained test plates was attached to the outside of a rotating drum suspended below the sea surface. The drum was rotated so that the speed of seawater against the test plate became 10 knots, a rotary test was performed for three months, and the difference between the initial film thickness and the film thickness after aging was measured to evaluate the self-polishing property. . Table 3 shows the test results.

[II] Simulation test A 10 cm x 10 cm x 1 mm sand-blasted copper plate was coated with a tar epoxy paint as an undercoat rust preventive paint with a coating thickness of 125 µm.
Times, and then apply a tar-vinyl intermediate coating
Coating was performed once at 70 μm. Next, Example 1-7, Comparative Example 1
-4 Each of the antifouling paints is applied three times with a coating film of 100 μm, and the obtained test plate is subjected to the above-mentioned rotary test for one month, and then immersed in a 1.5 m sea for one month. Thus, the test period was one cycle. A simulation test was performed assuming the operation of a ship, and the rust prevention for each cycle was indicated by the occupation area (%) of the formation of adhesion on the test coating film. The test results are summarized in Table 4. Table 5 shows the measurement results of the elution rate of copper.

(Unit μg / cm ² / day in the table) [Effects of the Invention] A specific water-soluble (or slightly soluble) polymer component of the present invention, a function of controlling the dissolution rate into seawater, and a microparticle capable of releasing an antifouling metal compound by hydrolysis in seawater by itself. The resin composition for an antifouling paint comprising a hydrolyzable resin component can form a strong and moderately water-soluble coating film.

Therefore, the resin composition for antifouling paints of the present invention can reduce the amount of antifouling agents to be incorporated into the paint, and has an antifouling system for a long period of time, so that it can be used for surface coating of ship bottoms, underwater structures, etc. It is extremely useful.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoichi Tatsuno 2-14-15 Yagi, Asaminami-ku, Hiroshima City, Hiroshima Prefecture (72) Inventor Shigeo Shimizu 1-10-19, Yoshishima Higashi, Naka-ku, Hiroshima City, Hiroshima Prefecture (56) References JP-A-58-42668 (JP, A) JP-A-62-57464 (JP, A)

Claims (1)

(57) [Claims] A water-soluble (co) polymer whose main component is methyl vinyl ether, N-vinylpyrrolidone, methoxyethylene glycol methacrylate, acrylamide, or at least one compound selected from rosin 0.1 to 30% by weight %, And a slightly hydrolyzable resin as a regulator of the dissolution rate into seawater obtained by copolymerizing the following monomers (i), (ii) and (iii): 70 to 90.99% by weight A resin composition for an antifouling paint comprising: ● (i). General formula ● (ii). General formula ● (iii). Vinyl acetate and / or C ₁ -C ₂ lower alkyl (meth) acrylate ...... 40-90 parts