JPH04230201A - Aquatic stainproof material - Google Patents

Abstract

PURPOSE:To obtain an aquatic stainpoof material having high safety, compared with a conventional organic tin compound and having excellent stainproof effect. CONSTITUTION:The objective aquatic stainproof material containing a biodegradable polymer having ester linkage in a main chain by which adhesion of acorn barnacle, Bugula neritina, sea squirt, algae, etc., onto the bottom of ship, fishing net, etc., is prevented.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an underwater antifouling material.

0002

BACKGROUND OF THE INVENTION It is well known that marine organisms such as barnacles, sea breams, sea squirts, and algae adhere to submerged parts of ships and offshore structures, causing various problems such as slowing down ships. Aquaculture nets and wire nets also become contaminated with marine organisms such as those mentioned above, making it difficult for seawater to flow through them, which can lead to the death of fish and shellfish and the outbreak of diseases.

[0003] In order to prevent the adhesion of these problematic marine organisms, methods using organic tin compounds have been applied, but in recent years, organic tin compounds that are toxic to the human body have been accumulating in fish and shellfish. Now that we know about it, there are moves to ban its use.

In response to this, there has been a search for organic compounds with antifouling activity that are less toxic than organotin compounds (for example, JP-A-1-175903, JP-A-62-77306, JP-A-61-64768, JP-A No. 61-257903, etc.), but so far nothing satisfactory has been found.

On the other hand, methods focusing on polymers as base materials have been studied, including a method using a resin containing an acid anhydride group (JP-A-2-99567) and a method using a metal ionomer resin having a carboxyl group in the side chain. (Unexamined Japanese Patent Publication No. 1-26861
0) etc. have been found. All of these methods are related to sustained release of metal compounds through hydrolysis, but because the rate of hydrolysis varies depending on the location where they are used, uniform effects cannot be expected.

In addition, new methods such as the method of JP-A-1-121372 that utilizes the slipperiness of silicone rubber and the method of JP-A-1-163108 that uses a chitosan-based porous molding material carrying a bacteriophage that lyses staining microorganisms have been developed. Ideas have also been proposed.

However, when silicone rubber is used, it is affected by abrasion resistance, scratches, and the shape of the object. When using phages, there are problems such as practical difficulties due to the large number of microorganisms that cause staining.

[0008]

[Problems to be Solved by the Invention] Recently, an underwater antifouling material has been developed using an efficient sustained release system to replace the conventional hydrolysis type sustained release system, and the resin released by decomposition is also environmentally friendly. There is a strong desire to develop a safe underwater antifouling material that does not contaminate water.

[0009]

[Means for Solving the Problems] The present invention provides a novel means using biodegradable polymers to solve the above-mentioned problems. That is, the present invention provides an underwater antifouling material characterized by containing a biodegradable polymer having an ester bond in its main chain. The antifouling agent of the present invention is required to contain a biodegradable polymer having an ester bond in the main ingredient, and in addition, an antifouling active substance,
It may also contain additives commonly used in antifouling agents.

[0010] As the biodegradable polymer of the present invention, for example, the following may be used. Those having an ester bond in the main chain are generally highly safe and can be expected to have stable effects because many microorganisms have decomposition activity.

Specific examples of these include poly(3-
hydroxybutyrate), 3-hydroxybutyric acid and 3-hydroxyvaleric acid copolymer, 3-hydroxybutyric acid and 4-hydroxybutyrate
A copolymer of hydroxybutyric acid, a polymer represented by the following formula, collectively called poly(3-hydroxyalkanoate)

0
012]

[Chemical formula 1]

(In the formula, R represents an alkyl group (approximately C3 to C15)) Aliphatic polyesters such as polylactic acid, polyglycolic acid, polymalic acid, polycaprolactone, polyvalerolactone, and polybutyrolactone can be mentioned. Poly(3-hydroxybutyrate), copolymer of 3-hydroxybutyric acid and 3-hydroxyvaleric acid, copolymer of 3-hydroxybutyric acid and 4-hydroxybutyric acid poly(3-hydroxyalkanoate), etc. are produced by microorganisms. It may be an optically active type, or an inactive type may be synthesized.

[0014] Furthermore, these can be modified by the following method. That is, by transesterifying the above polyesters with those same polyesters or with other polyesters,
A method of making a copolymer by reacting the above polyester with lactones such as β-propiolactone, γ-valerolactone, ε-caprolactone, etc. A method of making a copolymer by reacting the above polyester with aliphatic polyamide, etc. A method of adding a polyamide such as a polyamino acid to form a copolymer through an ester amidation exchange reaction, a method of adding a lactam such as ε-caprolactam to a polyester to form a copolymer, a method of adding an isocyanate such as tolylene diisocyanate to the above polyester. A method of modifying the above-mentioned polyester by reacting it with an aromatic polyester, A method of modifying the polyester by reacting it with ethylene oxide or propylene oxide, and introducing a polyoxyethylene group or a polyoxypropylene group. , a modification method using an epoxy compound, or a combination thereof.

Of course, polyesters based on aliphatic diols and aliphatic dicarboxylic acids can also be used, and polyesters modified in the same manner as above can also be used. Although not particularly limited to the above, as part of the constituent units of the biodegradable polymer having an ester bond in the main chain defined in the present invention,
Particularly good results are obtained when containing 3-hydroxybutyric acid units.

The biodegradable polymer of the present invention is preferably used alone, but may also be used in combination with other resins such as polyvinyl acetate,
Polyvinyl chloride, ethylene, vinyl acetate copolymers, polyacrylic esters, polymethacrylic esters,
It can also be used with well-known film-forming resins such as ethylene-maleic acid copolymers, styrene, maleic acid copolymers styrene, butadiene copolymers, and the like. The biodegradable polymer accounts for 5 to 100% by weight of the entire antifouling material, preferably 10% by weight of the entire antifouling material.
It is desirable that the amount is about 99% by weight.

As an embodiment of the present invention, when the composition further contains an antifouling active substance, extremely efficient sustained release of the antifouling active substance can be achieved. There are no particular restrictions on these antifouling active substances, but good results can be obtained when they are insoluble or sparingly soluble in water. Some examples of active substances include, but are not limited to, the following compounds. Copper compounds such as copper, cuprous oxide, basic copper carbonate, copper thiocyanate, copper hydroxide, silver compounds such as silver, silver carbonate, silver oxide, zinc compounds such as zinc, zinc oxide, halogen-substituted maleimides, Higher aliphatic amines such as dimethylstearylamine and didodecylmethylamine; sulfur-containing compounds such as isothiazolone, thiazole, and thiuram disulfide; organic compounds such as salicylanilide derivatives and alkylphenols; extracts from natural products such as Japanese knotweed and eucalyptus. etc.

[0018] These active substances may be used in an amount of about 0.1 to 80% by weight, preferably about 1 to 50% by weight of the entire antifouling material, depending on the strength of their effectiveness. As mentioned above, the composition of the antifouling material of the present invention can mainly include a biodegradable polymer having an ester bond in the main chain, an antifouling active substance, and various additives. Additives may be omitted in some cases.

As additives, additive resins other than the above-mentioned biodegradable polymers, pigments, dispersants, thickeners, organic solvents, etc. can be used. Additives are 1 to 60 of the total antifouling agent.
% by weight, preferably from 1 to 50% by weight.

[0020] The method for producing the antifouling material of the present invention involves dissolving or dispersing each of the above components in an organic solvent, and applying the organic solvent to the target ship bottom, fishing net, buoy, or other desired structure. There is a method of volatilizing it to form a film of antifouling material. Solvents used in this case include chloroform, 1,2
- Halogenated hydrocarbons such as dichloroethane, aliphatic esters such as ethyl acetate and ethyl lactate, ketones such as methyl ethyl ketone and methyl isobutyl ketone, lactones such as γ-butyrolactone, γ-valerolactone, and ε-caprolactone, dioxane, etc. Examples include ethers, pyridines, aromatic compounds such as toluene, xylene, and chlorobenzene, aprotic polar solvents such as N,N-dimethylformamide and dimethyl sulfoxide, and carbonates such as ethylene carbonate and propylene carbonate.

[0021] In addition, a method of forming a film by spraying the above-mentioned components in a molten state or a dispersed molten product containing an antifouling active substance onto an object with a spray gun, etc., and a method of forming a film by spraying the above-mentioned components in a molten state or a dispersed molten state containing an antifouling active substance, and a photopolymerizable method of acrylic acid esters, etc. A method of dissolving or dispersing monomers and photo-curing to form a film. Ball mills, sand grinders, and Raikai machines are used to form emulsions of ethylene-vinyl acid copolymers, ethylene-acrylic acid ester copolymers, polyvinyl acetate, etc. As a method of achieving a good dispersion state, the method of applying this to a target object and forming a film can be mentioned. The antifouling material of the present invention is most effective when used in the form of a film on an object. It is also possible to manufacture structures and nets themselves that require antifouling properties using the antifouling material of the present invention.

[0022]

[Action] The antifouling material of the present invention can be expected to have a stable antifouling effect over a long period of time. Regarding the mechanism, the following can be considered.

[0023] Since the antifouling active substance has a bactericidal effect, while it has an antifouling effect, there is no proliferation of microorganisms and the biodegradable polymer is not decomposed. However, over a long period of time, the antifouling active substance on the surface becomes deactivated and microorganisms begin to grow. Then, some types of microorganisms decompose the biodegradable polymer with extracellular enzymes, and the active substances inside the film come out to the surface, exerting the antifouling effect again. In this way, the controlled release of active substances is achieved by microorganisms.

[0024] Even when no antifouling active substance is added, a considerable antifouling effect is observed, so that among the many microorganisms that grow on the surface of biodegradable polymers, there are no adhesion substances that inhibit the growth of attached organisms. There are things that are like pathogens to living things.

[0025] ■ Adhesion of slimy slime, which is extremely easy to form on the surface, can be suppressed due to the surface condition.

[0026]

[Example] Next, the present invention will be explained in more detail with reference to an example. Examples 1 to 2 A copolymer of 3-hydroxybutyric acid and 3-hydroxyvaleric acid (molecular weight 670,000, 3-hydroxyvaleric acid units 20
% (Aldrich product), 0.3 g of cuprous oxide (finely pulverized product) in 20 g of 1,2-dichloroethane.
The mixture was dissolved and dispersed by heating at 0°C. This is 5cm x 15
It was applied to a zinc phosphate-treated iron plate of 1.5 cm, and the solvent was allowed to scatter in a natural state. A good film (antifouling material) was formed, and the film thickness was about 100 μm. In addition, as Example 2, the film thickness,
An antifouling film having the same composition as in Example 1 and having a thickness of 20 μm was formed.

Examples 3 to 7 Similarly, as antifouling active substances, p-nonylphenol,
0.2g (Example 3) Daconil 0.2g (Example 4),
Thiabendazole 0.4g (Example 5), copper powder 0.3g
(Example 6) and 0.3 g of basic copper carbonate (Example 7) were used to form an antifouling material film. Film thickness is 100-125μ
It was m.

Reference example 1. Poly-3-hydroxybutyrate (molecular weight 800,000, derived from microorganisms, Aldrich product) was added to
In the presence of caprolactone and 0.02 times the weight of methanesulfonic acid, heat and reflux in 1,2-dichloroethane for 10 hours to react. After the reaction is complete, pour into 10 times the weight of methanol and remove the formed precipitate by filtration. A copolymer of 3-hydroxybutyric acid and ε-caprolactone was obtained. Yield is 9
It was 2%. The weight average molecular weight was 65,000 and the number average molecular weight was 31,000. This one is poly(3-
Hydroxybutyrate) formed a better film than that alone. It was also confirmed that it was biodegradable using activated sludge.

Example 8 2 g of the copolymer obtained in Reference Example 1, cuprous oxide (finely pulverized product)
0.3 g was dissolved and dispersed in 20 g of methyl isobutyl ketone by heating at 50°C. This was applied to a 5 cm x 15 cm iron plate treated with zinc phosphate, and the solvent was allowed to scatter in a natural state. A good film was formed. Film thickness is approximately 100μm
Met.

Examples 9 to 11 As in Example 8, as antifouling active substances, 0.2 g of p-nonylphenol (Example 9), 0.2 g of Daconyl (Example 10), and 0.3 g of copper powder (Example 11) was used to form an antifouling material film. The film thickness was approximately 200 μm.

Example 12 In Example 1, a film made only of biodegradable polymer was formed without adding any antifouling active substance. The film thickness was 125 μm.

Example 13 1 g of the copolymer of 3-hydroxybutyric acid and 3-hydroxyvaleric acid used in Example 1 and 1 g of cuprous oxide were added to 10 g of a 20% ethylene acid bicopolymer emulsion. Thoroughly mixed in a machine. This was applied onto a 5 cm x 15 cm iron plate treated with zinc phosphate and allowed to dry. A film with a thickness of 200 μm was formed.

Comparative Example 1. 0.5 cuprous oxide in 3 g of fast-curing epoxy resin (2-component type)
g was dispersed and applied onto a 5 cm x 15 cm iron plate treated with zinc phosphate to form a film of 125 μm.

Comparative Example 2. 5cm x 15cm using only commercially available acrylic emulsion paint
Painted on a zinc phosphate treated iron plate with a thickness of about 12cm and dried.
A film of 5 μm was formed.

Antifouling Performance Test The test pieces with antifouling materials prepared in the Examples and Comparative Examples were subjected to an immersion test in Fukuyama Bay, Hiroshima Prefecture from March to July, and the following results were obtained. The antifouling performance is shown in three stages: ○△×. The effects are displayed in decreasing order. (However, ○ includes cases where the slime is attached)

Examples or immersion
Soaking Soaking Soaking
Comparative example no. 1 month later 2 months later 3 months later 4 months later Example 1
○ ○
○ ○
2 ○ ○
○＊ ×
3 ○ ○
○ △
4 ○
○ ○ ○
5 ○
○ △
× 6 ○
○ ○
○ 7
○ ○ ○
○ 8
○ ○
○ × 9
○ ○
○ △ 10
○ ○
○ ○
11 ○ ○
○ ○
12 ○ ○
× ×
13 ○
○ ○ ×
Comparative example 1 ○
△ × ×
2 ×
× ×
×*: Part of the film was peeled off.

Reference Example 2 3 g of poly-3-hydroxybutyric acid in a 50 ml four-necked flask
, 30 g of anhydrous 1,2-dichloroethane, and 0.05 g of methanesulfonic acid were charged and dissolved at 85°C. 4 g of 6-hexanolide was added dropwise thereto over about 2 hours. After this, after reacting for 10 hours, OCN(CH2)6
1 ml of NOC was added and reacted. (The number average molecular weight at this time is Mn=3.1×104, and OCN(CH2
) 6 NCO was used in about 25 times the molar amount. )6
After reacting for an hour, the reaction mixture was poured into 200 ml of acetone to form a precipitate. The precipitate was filtered off and dried under vacuum. In this way, low polymers and the like were removed in one step, and 5.1 g of a copolymer fractionated with acetone was obtained. The weight average molecular weight of this product is Mw=8.5×104, Mn=5.3×104
It had a molecular weight distribution of Mw/Mn=1.6. The N content according to elemental analysis was 0.18%. Further, caloethanol decomposition was carried out using sulfuric acid as a catalyst, and the composition of 3-hydroxybutyric acid units and 6-hydroxycaproic acid units was determined by gas chromatography to be 1:0.53.

Examples 14 to 16 Antifouling material films were formed using cuprous oxide as the antifouling active substance and changing the type of resin. Add 20 g of 1,2-dichloroethane as a solvent, 2 g of resin, and 2 g of cuprous oxide, and add 50 g of 1,2-dichloroethane.
The mixture was heated and dissolved at ℃ and further dispersed. This was applied to a 5 x 15 cm iron plate coated with epoxy powder paint, and the solvent was scattered to form a film. The film thickness was adjusted to approximately 100 μm.

The following resins were used. Resin obtained in Reference Example 2 (Example 14), copolymer of 3-hydroxybutyric acid and 3-hydroxyvaleric acid used in Example 1 (Example 15), copolymer of 3-hydroxybutyric acid and 3-hydroxyvaleric acid When combined, the 3-hydroxyvaleric acid content is 14%.
Weight average molecular weight 750,000 Number average molecular weight 4
00,000 (Example 16).

Example 17 Using the same resin as in Example 16, except for cuprous oxide, a resin-only film was formed. (Thickness approx. 100μm)

004
1] Example 18 2 g of polycaprolactone (Plaxel H-4 manufactured by Daicel Corporation) with a number average molecular weight of 40,000 was dissolved in 20 ml of xylene, and a film of about 100 μm was formed on an iron plate coated with an epoxy powder coating. .

Example 19 Poly-3-hydroxybutyric acid (molecular weight 800,000, microbial origin,
Aldrich product) 1.8g. Resin 0 obtained in Reference Example 2
．． 2 g of 1,2-dichloroethane was heated and dissolved at 50° C., and a film of about 100 μm was formed in the same manner.

Comparative Example 3 Comparative Example 3 was prepared by using an iron plate coated only with epoxy powder paint and without an antifouling material.

Comparative Example 4 2 g of cuprous oxide was dispersed in 2 g of fast-curing epoxy resin (two-component type), and the coated iron plate used in Comparative Example 3 was coated with a thickness of about 100 μm.
A film of m was formed.

Antifouling Performance Test Test pieces of the antifouling materials prepared in Examples and Comparative Examples were subjected to an immersion test in a bay in Fukuyama City, Hiroshima Prefecture from May to September, and the following results were obtained. Antifouling performance ○△×
It is shown in three stages. They are displayed in this order so that the effect decreases. (However, ○ includes cases where the level of slime is attached.)
During the test, there were no problems with the adhesion of the antifouling material in any case.

Examples or immersion
Soaking Soaking Soaking Comparative Example No. 1 month later 2 months later
After 3 months After 4 months Example 14
○ ○ ○
○ 15
○ ○ ○
○ 16
○ ○ ○
○ 17
○ ○ △＊
× 18
○ △ △
× 19
○ ○ ○
△*Comparative example 3 ×
× ×
× 4
○ × ×
×*: The antifouling material film had disappeared in some places.

[0047] The test results showed that the antifouling material according to the present invention had good performance.

[0048]

[Effects of the Invention] An antifouling material with high performance, nontoxicity, and high safety was obtained.

Claims (1)

[Claims] Claim 1: An underwater antifouling material characterized by containing a biodegradable polymer having an ester bond in its main chain.