Antifouling paints composition

Antifouling paints composition

The present invention relates to an antifouling paint composition, and more particularly, to an antifouling paint composition in which a much larger amount of an antifouling enzyme is supported than a conventional antifouling composition containing an antifouling enzyme.

The purpose of the antifouling coating composition is to prevent or control the adhesion and growth of marine organisms that cause surface contamination of the seawater immersion coating film. When the hull bottom (bottom part) and underwater structures are exposed to water for a long period of time, animals such as clams, oysters, crustaceans and mussels, plants such as green seaweed (seaweed), and various aquatic organisms such as aquatic bacteria attach to the surface, It proliferates, resulting in poor appearance or loss of function. In particular, when these aquatic organisms attach to and proliferate at the bottom of the ship, the surface roughness of the entire ship's shell increases, which may lower the ship's speed or increase fuel consumption. In order to remove aquatic organisms from the bottom of the ship, more effort and long working hours are required. In addition, when mucus (mud material) or slime attaches on the bacteria that attach to and propagate underwater structures and rot bacteria, or when large organisms with adhesiveness attach to and propagate underwater structures (eg steel structures), In the case of damaging the corrosion protection coating of an underwater structure, there is a problem in that the strength or function of the underwater structure is lowered, thereby significantly shortening the lifespan.

In order to prevent this problem, a copolymer such as tributyltin methacrylate and methyl methacrylate and cuprous oxide (Cu)₂It is common to apply an antifouling paint composition containing O).

The copolymer constituting this antifouling paint composition is hydrolyzed in seawater, and bistributyltin oxide (Bu₃Sn-OSnBu₃(Bu is a butyl group)) or tributyltin halide (Bu₃It emits an organotin compound such as SnX (where X is a halogen atom)), thereby exhibiting an antifouling effect. In addition, since the copolymer is a hydrolyzable self-polishing paint, the hydrolyzed copolymer itself is also changed to water-soluble and dissolved in seawater, so that no resin residue is left on the surface of the ship's coating film and it has continuous activity. keep the surface

However, the aforementioned organotin compounds are highly toxic and highly likely to cause marine pollution, generation of malformed fish or clams, and destruction of aquatic ecosystems through the food chain. Due to these problems, the development of a tin-free antifouling paint capable of replacing the conventional organic tin antifouling paint has been required.

Recently, in order to replace tin, various materials such as zinc, copper, silyl, silicon, copper dioxide, and the like and materials with good abrasion resistance have been used. Existing paints use a partially gelled binder by mixing a metal ester compound such as metal acetate with an acid group-containing polymer. These binders had poor film forming ability and storage properties, which resulted in cracks, poor abrasiveness, and difficult application due to high viscosity. In addition, the conventional acrylic polymer mixed with a metal ester compound, such as zinc acrylate, and added polymerization type, has a problem in that it is unstable in long-term wearability because the degree of wear control is not good.

In addition, it is reported that these substances also contain heavy metals and have an adverse effect on the ecosystem.

Accordingly, Korean Patent Application No. 2001-7010883 discloses an antifouling composition for ships including an antifouling enzyme or a microorganism producing the same in epoxy or glass fiber. In addition, Korean Patent Application No. 2002-7012611 discloses an antifouling composition comprising rosin and an antifouling enzyme, and the rosin has an immobilizing effect on the antifouling enzyme and serves to prevent the antifouling enzyme from being discharged to the outside. However, all of these prior technologies have a problem in that the amount of the antifouling enzyme fixed to the support is extremely small, and the antifouling effect is not only low, but also the antifouling enzyme is easily leaked to the outside over time, so that the antifouling effect is rapidly reduced.

<p>As described above, the conventional antifouling paint composition containing an antifouling enzyme has a problem that not only has remarkably low antifouling performance when applied to actual industry due to excessively low activity, but also has a problem that the antifouling effect sharply decreases over a long period of time. . </p><p>Accordingly, the present invention has been devised to overcome the above-mentioned problems, and the problem to be solved by the present invention is that it contains a significantly larger amount of antifouling enzyme compared to the conventional composition for antifouling containing an antifouling enzyme, and even with the passage of time An object of the present invention is to provide an antifouling paint composition comprising an antifouling composition in which an antifouling enzyme hardly leaks to the outside.</p>

<p>The present invention has been devised to solve the above problems, and an object of the present invention is to provide an antifouling enzyme-porous carrier complex comprising a porous carrier and an antifouling enzyme supported inside the pores of the carrier.</p><p>In one embodiment according to the present invention, the present invention provides a paint composition in which an antifouling enzyme-porous carrier is mixed with a paint.</p><p>Here, the antifouling enzyme may be supported inside the porous carrier to form a complex by crosslinking.</p><p>The porous carrier may be selected from the group consisting of silica, alumina, niobium, tantalum, zirconium, carbon, magnesium, and titanium. </p><p>The antifouling enzyme is any one selected from the group consisting of acylase, lactonase, protease, peroxidase, aminopeptidase, phosphatase, transaminase, serine-endopeptidase, cysteine-endopeptidase and metalloendopeptidase. There may be more than one. </p><p>According to another embodiment of the present invention, the porous carrier may include magnetic nanoparticles.</p><p>According to a preferred embodiment of the present invention, the pore size inside the porous carrier may be 1 ~ 1000nm.</p><p>According to another preferred embodiment of the present invention, the porous carrier may or may not include a functional group capable of covalently bonding with an enzyme therein.</p><p>According to another preferred embodiment of the present invention, the antifouling enzyme-porous carrier complex may be included in an amount of 0.01 to 50% by weight based on the total paint composition.</p><p>A method for preparing a coating composition according to an embodiment of the present invention includes the following steps: </p><p>(1) adsorbing the antifouling enzyme into the pores of the porous carrier; </p><p>(2) forming a porous carrier-antifouling enzyme complex by adding a crosslinking agent to the porous carrier to which the antifouling enzyme is adsorbed to form crosslinks between the antifouling enzymes; and</p><p>(3) mixing the porous carrier-antifouling enzyme complex with a paint</p><p>In the above, the antifouling enzyme complex may have a diameter greater than the inlet size of the pores of the porous carrier. Therefore, it cannot easily escape from the pores of the porous carrier and can be stably immobilized in the carrier.</p><p>Alternatively, as another embodiment of the present invention, an antifouling enzyme complex may be prepared by simultaneously adding an enzyme and a crosslinking agent to the porous carrier in step (1). </p><p>The crosslinking agent is diisocyanate, dianhydride, diepoxide, dialdehyde, diimide, 1-ethyl-3-dimethyl aminopropylcarbodiimide, glutaraldehyde, bis(imido ester), bis(succinimidyl) ester) and one or more selected from the group consisting of diacid chloride. </p>

<p>The antifouling paint composition comprising the antifouling enzyme-porous carrier complex of the present invention can obtain improved antifouling performance compared to the existing antifouling enzyme-substrate complex, which has been limited in industrial application due to excessively low antifouling enzyme activity, thereby increasing industrial applicability In addition to increasing the cost, it is possible to solve the economic problem by using a low-cost support.</p><p>In addition, if it is developed and used as a paint material by mixing with various polymer materials widely used as paint materials, it can be effectively applied to various industrial fields where antifouling materials are used (shipping and port industry, fluid transportation industry, water treatment industry, etc.) Therefore, it can be used as a substitute for the existing chemical antifouling substances, which are limited in use due to environmental pollution.</p>

1 is a schematic diagram showing a process of immobilizing antifouling enzymes after making spherical porous silica into magnetic-porous silica. 2 shows an image of a commercially available spherical porous silica material (left) and magnetic-porous silica (right) to which magnetic nanoparticles are chemically attached. 3 is a photograph of an antifouling enzyme-magnetic-porous silica antifouling material separated from a solution using a magnetic field formed by a magnet. 4 is an antifouling enzyme using a fluorescence-spectrophotometer (Free AC), a magnetic-porous silica complex adsorbed with an antifouling enzyme (ADS-AC/Mag-S-MPS), and a magnetic-porous silica crosslinked after adsorption of an antifouling enzyme Shows the measured values of the initial rate of the complex (NER-AC/Mag-S-MPS). 5 is an experiment conducted to confirm the antifouling action of the magnetic-porous silica complex (NER-AC/Mag-S-MPS) cross-linked after adsorption of the antifouling enzyme under the conditions in which the biofilm is formed, and the contamination proceeds as it is. Antifouling enzyme under the conditions of (a, wastewater + S. -This is a result of comparing the conditions (c, wastewater + S. Aeruginosa + NER-AC/Mag-S-MPS) with magnetic-porous silica material. The graph shows the relative permeability values over time with respect to the initial permeability values by checking the permeability of the membrane filter induced to contamination under each condition. 6 is a schematic diagram of equipment installed for measuring permeability. FIG. 7 shows images as a result of observing the surface of the separator induced contamination through a confocal scanning microscope under each of the conditions shown in FIG. 5 . 8 is a schematic diagram illustrating an apparatus for measuring a trans-membrane pressure (TMP) that is changed by biofilm formation when a flow through the membrane filter is induced at a constant flow rate. 9 is an experimental result of measuring the permeation pressure (trens membrane pressure, TMP) according to the biofilm formation under the condition that only the paint was applied to the separation membrane filter and the antifouling enzyme-magnetic-porous silica and the mixture of the paint was applied to the separation membrane filter am.

Hereinafter, the present invention will be described in more detail through examples. These examples are only for illustrating the present invention in more detail, and it will be apparent to those of ordinary skill in the art that the scope of the present invention is not limited by these examples according to the gist of the present invention. .

The term 'antifouling enzyme' refers to an enzyme that is included in an antifouling composition and prevents the attachment and growth of contaminants on the surface of a material through a biological antifouling action. For example, the surface attachment and growth of biological contaminants is carried out by a unique quorum sensing system, and the quorum sensing materials are compounds of the N-acyl homoserine lactone (AHL) family, which are antifouling enzymes. By hydrolyzing this compound, it acts to disable signal transduction (quorum quenching). Meanwhile, antifouling enzymes disclosed in Korean Patent Application No. 2001-7010883 and Korean Patent Application No. 2002-7012611 may be included in the present invention.

The term 'porous carrier' refers to a carrier having a plurality of pores with a size of 1 to 1000 nm therein, and depending on the size of the pores, microporous (pore &lt; 2 nm), mesoporous (2 nm &lt; pore &lt;) 50 nm) and macroporous (pore &gt; 50 nm) materials.

1 is a schematic diagram showing the step of supporting the enzyme inside the pores of the porous carrier.

First, the magnetic nanoparticles are supported inside the pores of the porous carrier, and then the enzyme is filled into the inside of the porous carrier. Then, enzymes are adsorbed inside the pores of the porous carrier as shown in the lower right of FIG. 1 . However, except for some enzymes adsorbed on the inside of the porous carrier, the remaining enzymes are contained inside the pores without any special binding, so when a liquid is introduced from the outside or external pressure is applied, the remaining enzymes except for some adsorbed enzymes are on the porous carrier. will leak out of the In addition, some of the adsorbed enzymes also lose their adsorption power over time, and eventually leak to the outside. Due to this, the stability of the enzyme of the porous carrier is deteriorated.

In contrast, when a crosslinking agent is added to the enzymes contained in the pores, crosslinks are formed between the enzymes adsorbed inside the pores and the enzymes that are not adsorbed to form an enzyme complex. As a result, the cross-linked enzyme complex becomes larger than the size of the pore inlet of the porous carrier. Since the enzyme assembly is located, the interior of the porous carrier is not modified to form a functional group capable of covalently bonding with the enzyme, so even if a direct binding relationship such as a covalent bond between the porous carrier and the antifouling enzyme is not formed, the antifouling enzyme assembly is located inside the porous carrier. can be provided for a long period of time.

First, the porous carrier used in the present invention will be described. As long as it is a porous carrier typically used to support an enzyme, it may be used without limitation. Preferably, the porous carrier may be any one or more selected from the group consisting of silica, alumina, niobium, tantalum, zirconium, carbon, magnesium, and titanium, and MPS (mesoporous silica), MCM (mobil composition of matter), It can be used in the form of SBA (Santa Barbara materials), CNS (MPS with cyano-funtional groups), OMC (ordered mesoporous carbon), MCF-C (mesocellular carbon foam) or SCMS (supplementary cementitious materials), preferably MCF (mesocellular foam).

On the other hand, the antifouling enzyme that can be used in the present invention can be used without limitation as long as it is supported in the porous carrier and can generate an antifouling effect in the paint, preferably acylase, lactonase, protease, peroxidase, Any one selected from the group consisting of aminopeptidase, phosphatase, transaminase, serine-endopeptidase, cysteine-endopeptidase and metalloendopeptidase may be used in combination, but is not limited thereto.

[Preparation example]

<b>Magnetic-porous silica material preparation</b>

Magnetic-porous silica for the immobilization of the antifouling enzyme used a method of immobilizing magnetic nanoparticles on a porous silica material by chemical deposition. 1 g of spherical mesoporous silica and 0.5 g of Fe(NO₃)₃9H₂O was prepared by dissolving in 20 ml of ethanol. After stirring at room temperature until the ethanol solution was completely evaporated, the remaining sample was completely dried while raising the temperature from 100°C to 400°C at 3°C per minute to prepare magnetic-porous silica.

[Comparative example]

<b>antifouling enzyme</b><b> adsorption method </b><b>antifouling enzyme</b><b> Fixing method (</b><b>Enzyme</b><b></b><b>adsorption</b><b>, </b><b>ADS</b><b>)Depending on the </b><b>antifouling enzyme</b><b>-Manufacturing of magnetic-porous composites</b>

The magnetic-porous silica prepared in Example 1 was mixed with an antifouling enzyme (acylase, acylase, AC) to synthesize magnetic-porous silica to which an antifouling enzyme was adsorbed. Specifically, 10 mg of the magnetic-porous silica prepared in Example 1 and 1.5 ml of an antifouling enzyme are mixed in a 2 ml centrifuge tube, and the antifouling enzyme is prepared at a concentration of 2 mg/ml in 100 mM phosphate buffer. was used. The prepared antifouling enzyme-magnetic-porous silica mixture was stirred at 50 rpm using a stirrer at room temperature for 30 minutes. Through this process, the antifouling enzyme is adsorbed to the surface of the magnetic-porous silica pores. In order to remove the non-adhered antifouling enzyme and cap the unreacted antifouling enzyme attached functional group remaining on the polymer nanofiber, the supernatant is removed after centrifugation and 200 mM Tris buffer is used with a stirrer for 30 minutes. It was stirred at rpm. After the capping reaction was completed, 100 mM phosphate buffer was used to wash the remaining Tris buffer.

<p><b>antifouling enzyme</b><b> after adsorption </b><b>cross-linking method</b><b> used </b><b>antifouling enzyme</b><b>-Manufacturing of magnetic-porous silica composite</b></p><p>The complex was prepared by mixing the magnetic-porous silica prepared in Example 1 and an antifouling enzyme (acylase, acylase, AC), and then adsorbing the antifouling enzyme and then crosslinking the complex by an antifouling enzyme fixation method (nanoscale enzyme reactor, NER). synthesized. Specifically, by mixing the magnetic-porous silica prepared in Preparation Example and an antifouling enzyme (acylase, acylase, AC), the magnetic-porous silica to which the antifouling enzyme is adsorbed was synthesized. Specifically, 10 mg of the magnetic-porous silica prepared in Preparation Example and 1.5 ml of an antifouling enzyme are mixed in a 2 ml centrifuge tube, and the antifouling enzyme is prepared at a concentration of 2 mg/ml in 100 mM phosphate buffer. was used. The prepared antifouling enzyme-magnetic-porous silica mixture was stirred at 50 rpm using a stirrer at room temperature for 30 minutes. Through this process, the antifouling enzyme is adsorbed to the surface of the magnetic-porous silica pores. Then, to induce crosslinking through covalent bonding between the adsorbed antifouling enzymes, glutaraldehyde, a crosslinking agent, was added to 0.1% of the total volume. For sufficient crosslinking, the mixture was stirred at 50 rpm using a rocker at room temperature for 2 hours. To remove the non-adhered antifouling enzyme and cap the unreacted antifouling enzyme-attached functional group remaining on the magnetic-porous silica, the supernatant was removed after centrifugation, and 100 mM Tris buffer was used for 30 minutes using a stirrer. It was stirred at 200 rpm. After the capping reaction was completed, 100 mM phosphate buffer was used to wash the remaining Tris buffer. After the antifouling enzyme prepared through this process is adsorbed, the antifouling enzyme-magnetic-porous silica complex (NER-AC/Mag-S-MPS) using the nanoenzyme reactor method is stored at 4°C until use until use without a decrease in activity. storage is possible.</p>

<p><b>antifouling enzyme</b><b>-Magnetic-porous silica composite </b><b>antifouling enzyme</b><b> Activity and stability measurements</b></p><p>Antifouling enzyme-adsorbed magnetic-porous silica complex (ADS-AC/Mag-S-MPS) prepared in Example 1 and Comparative Example, nanoscale enzyme reactor (NER) method (crosslinking) after adsorption of antifouling enzyme The antifouling enzyme activity of the antifouling enzyme-magnetic-porous silica complex (NER-AC/Mag-S-MPS) was measured using a fluorescence-spectrophotometer (Spectrofluorophotometer, Shimadzu RF-5301). </p><p>Specifically, the antifouling enzyme-polymer nanofiber complex stored at 4°C was prepared by diluting it to 0.5 mg/ml based on the weight of magnetic-porous silica using 100 mM phosphate buffer. Then, 10 mM of N-acetyl-L-methionine is prepared as a reaction solution, and 1.9125 mg of N-acetyl-L-methionine is dissolved in 100 mM phosphate buffer. Antifouling enzyme activity was measured using these two solutions. To measure the activity of the antifouling enzyme, 1 ml of the antifouling enzyme-magnetic-porous silica complex and 1 ml of a 10 mM N-acetyl-L-methionine solution were mixed and N-acetyl-L-methionine was stirred for a set period of time. of the decomposition reaction was carried out. N-acetyl-L-methionine is decomposed into acetic acid and L-methionine by an antifouling enzyme, and the decomposed L-methionine is reacted with an OPA solution in which 0.1 mg of o-phthalaldehyde (OPA) is dissolved in 50 mM sodium borate buffer. becomes fluorescent. With time, the amount of L-methionine capable of binding to the OPA material increases, and accordingly, the fluorescence value shown on the fluorescence-spectrophotometer also increases.</p><p>Figure 4 shows the relative value of activity when the activity value of the first day of activity confirmation is 100 for the results of measuring the activity of Free AC, ADS-AC/Mag-S-MPS, NER-AC/Mag-S-MPS samples shown graphically. </p><p>As can be seen from FIG. 4 , it was confirmed that the antifouling enzyme-magnetic-porous silica complex (NER-AC/Mag-S-MPS) using the crosslinking method after adsorption of the antifouling enzyme had the best antifouling enzyme activity stability. As a result of measuring the activity of the antifouling enzyme-polymer nanofiber complex in 100 mM phosphate buffer at room temperature using a stirrer at 200 rpm, it was confirmed that the active half-lives of free AC and ADS-AC were less than 1 day and 5 days, respectively However, the activity of NER-AC was maintained at 80% or more until the time point of 33 days, showing a stabilized activity.</p>

<p><b>Through checking the permeability of the contamination-induced separation membrane filter </b><b>antifouling enzyme</b><b>-Check the biofilm formation inhibition performance of the magnetic-porous silica composite.</b></p><p>The antifouling enzyme activity of the antifouling enzyme-magnetic-porous silica complex (NER-AC/Mag-S-MPS) prepared in Example 1 was created under conditions in which contamination was induced in the separation membrane filter, and a biofilm generated on the surface of the separation membrane filter We observed the change of pitch determined by</p><p> Specifically, the condition in which the contamination proceeds as it is (a, wastewater (39.5 ml) + S. Aeruginosa (0.5 ml)), the condition in which the magnetic-porous silica material is added to the condition in which the contamination proceeds (b, wastewater (38.7 ml) + S .Aeruginosa (0.5 ml) + Mag-S-MPS (0.8 ml of 0.5 mg/ml)), antifouling enzyme-magnetic-porous silica material in the condition of contamination (c, wastewater (38.7 ml) + S A sample of Aeruginosa (0.5 ml) + NER-AC/Mag-S-MPS (0.8 ml of 0.5 mg/ml)) was prepared and the membrane filter was recovered at intervals of 1 day. For the recovered membrane, using the apparatus shown in FIG. 6 , the time taken for 10 ml of distilled water to pass through the membrane under a pressure of 10 kPa was measured. The graph shown in FIG. 5 shows the relative permeability values over time with respect to the initial permeability values by checking the permeability of the membrane filter induced to contamination under each condition. As a result of measuring the permeability, the condition in which the contamination proceeds as it is (a, wastewater (39.5 ml) + S. 38.7 ml) + S. aeruginosa (0.5 ml) + Mag-S-MPS (0.8 ml of 0.5 mg/ml)) showed less than 50% of the relative permeability of the initial value after 3 days. Conditions with antifouling enzyme-magnetic-porous silica material (c, wastewater (38.7 ml) + S. Aeruginosa (0.5 ml) + NER-AC/Mag-S-MPS (0.8 ml of 0.5 mg/ml)) maintained relative permeability of 50% or more for more than a week, and the rapid decrease in flow shown in the other samples of FIG. was not observed. These results indicate the excellent antifouling effect of the NER-AC/Mag-S-MPS sample.</p>

<p><b>Through confirmation of biofilm of contamination-induced separation membrane filter </b><b>antifouling enzyme</b><b>-Check the biofilm formation inhibition performance of the magnetic-porous silica composite.</b></p><p>The antifouling enzyme activity of the antifouling enzyme-magnetic-porous silica complex (NER-AC/Mag-S-MPS) prepared in Example 1 was created under conditions in which contamination was induced in the separation membrane filter, and a biofilm generated on the surface of the separation membrane filter The surface of the CLSM (confocal laser scanning microscope) was confirmed.</p><p>Specifically, the condition in which the contamination proceeds as it is (a, wastewater (39.5 ml) + S. Aeruginosa (0.5 ml)), the condition in which the magnetic-porous silica material is added to the condition in which the contamination proceeds (b, wastewater (38.7 ml) + S .Aeruginosa (0.5 ml) + Mag-S-MPS (0.8 ml of 0.5 mg/ml)), antifouling enzyme-magnetic-porous silica material in the condition of contamination (c, wastewater (38.7 ml) + S Prepare a sample of aeruginosa (0.5 ml) + NER-AC/Mag-S-MPS (0.8 ml of 0.5 mg/ml) and collect the separator filter every 1 day to check the confocal laser scanning microscope (CLSM) image and the results are shown in FIG. 7 .</p><p>As can be seen in FIG. 7 , the CLSM image of the sample containing the antifouling enzyme-magnetic-porous silica complex (NER-AC/Mag-S-MPS) using the nanoscale enzyme reactor (NER) method after adsorption of the antifouling enzyme It was observed that biofilm formation was suppressed through comparison of the color density and color distribution of the biofilm expressed in green. </p>

<p><b>on the surface of the separator filter </b><b>antifouling enzyme</b><b>-Biofilm formation inhibition performance was confirmed by applying a coating composition in which the magnetic-porous silica composite was mixed.</b></p><p>The antifouling enzyme-magnetic-porous silica complex (NER-AC/Mag-S-MPS) prepared in Example 1 was mixed with the paint and applied to the surface of the separator filter, and the conditions inducing contamination on the separator filter After the composition, the pressure that changes depending on the presence or absence of the biofilm formation was measured under the condition that it permeates through the separation membrane filter at a constant flow rate.</p><p>Specifically, if a flow is formed in the separation membrane filter at a constant flow rate using the device of FIG. 8, the pressure (trans-membrane) for maintaining the flow rate lowered by the biofilm generated on the surface of the separation membrane filter at the initial set flow rate (trans-membrane) pressure, TMP) increases. According to the experimental results of FIG. 9, in the case of the membrane filter coated with only the paint, it was observed that the TMP was increased by the biofilm formed over time, while the antifouling enzyme-magnetic-porous silica mixed coating was applied. In the case of the filter, it was confirmed that the biofilm formation was suppressed and the TMP increase trend was slowed down.</p>

The antifouling paint composition of the present invention can be usefully used to prevent or control the adhesion and growth of organisms.