JP2007084775A - Antifouling resin agent and antifouling coating agent - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antifouling coating composition preventing attachment of aquatic life by being coated on an aquatic structure, a fishing net, a water intake of a nuclear power plant, etc. <P>SOLUTION: The antifouling coating composition comprises a hydroxylated polybutadiene, a melamine resin and a colored pigment of essential components regulated so that the total proportion of the hydroxylated polybutadiene, the melamine resin and the colored pigment in the solid components may be 20-50 wt.%, 50 wt.% of other solid components may be silica fine particles containing ≥10 wt.% component having ≤1μm particle diameter, and the remainder may be alumina fine particles containing ≥10 wt.% component having ≤1 μm particle diameter. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention mixes resin in floating structures, bridges, fishing gear, fishing nets, aquaculture tanks, seaplanes, pleasure boats, ships, water motorbikes, nuclear water intakes, especially pleasure boats with a relatively long mooring period. In addition, the present invention relates to a resin agent and a coating agent that are used for the purpose of preventing adhesion of underwater organisms by applying a resin.

  Underwater creatures represented by various shellfish that are animals and various algae that are plants are the underwater parts (hereinafter referred to as the ship's bottom) of vessels that are parked, floating structures, bridges, fishing gear, fishing nets, aquaculture tanks, and water It has the property of adhering to airplanes, pleasure boats, water motorbikes, and nuclear water intakes to secure its own living area.

  Once aquatic organisms adhere to the bottom of a ship / pleasure boat, energy is consumed due to fluid resistance resulting from the relative motion of the aquatic organism and water during navigation of the vessel / pleasure boat, resulting in a decrease in navigation speed and energy loss at the same propulsion energy. With the undesirable consequence of the occurrence of

  The aquatic organisms adhere to the bottom of the ship when the ship is stopped or moored when the relative speed between the bottom and the water is zero. For this reason, this problem with respect to pleasure boats with a long underwater mooring period during a certain period, in other words, a low availability factor, is serious.

  If aquatic organisms above a certain standard adhere to a ship or pleasure boat, it is common practice to pull them up to a dry dock, etc., peel off and remove the aquatic organisms by mechanical means, and then apply antifouling paint if necessary. is there. In the case of a pleasure boat, the period when the leisure season in the summer is ahead and the autumn season when the leisure season is over are the time when such treatment is most performed.

  As Japan's first patent right is this kind of paint, the technology development of this kind of paint has a long history. This kind of paint is required to have the function of preventing adhesion of aquatic organisms in addition to the durability and weather resistance required for general paints. As a means to achieve such functionality that does not attach aquatic organisms, it contains toxic substances that kill attached aquatic organisms, it contains substances that aquatic organisms avoid, and aquatic organisms are difficult to attach physically and electrochemically. Measures are taken, such as mixing in substances that become.

  Until now, the mainstream method was to mix toxic substances into the paints that biochemically kill aquatic organisms. In the past, organotin compounds were often used because of their remarkable killing ability. However, it is now banned internationally due to concerns that environmental pollution in harbors caused by the accumulation of organotin compounds dissolved in seawater has a serious adverse impact on the ecosystem. Instead, many copper compounds are now used, but this is also considered to follow the same process as organotin due to environmental pollution problems.

  There is also considerable interest in paints that contain substances that are repelled by aquatic organisms as biochemical countermeasures, but many of these paints have not yet been able to clear issues such as durability. .

  Unlike the biochemical countermeasures, the present invention belongs to an antifouling resin agent and an antifouling coating agent, which are kneaded with substances that make it difficult to attach aquatic organisms physically and electrochemically. As a prior invention having high similarity to the present invention, there is one in which silica sol having an average particle size of silica fine particles of 5 to 100 μm is kneaded with an acrylic resin. (See Patent Document 1)

  In the present invention, when the average particle size is less than 5 μm, there is a fear that the stability of the silica sol may be lacking, which is not preferable. However, the present invention is a completely different invention based on the basic principle that it has a very effective underwater organism adhesion and antifungal action rather than having a small particle size, which is avoided as the above-mentioned prior invention is not preferable.

The inventor of the present invention has already filed a patent for an antifouling effect resin agent in which allophane, which is an alumina-silicate material, is finely powdered and kneaded into a resin / pigment for the purpose of solving the same problem as the present invention described later. I would like to mention that this is one of the background technologies. (See Patent Document 2)
JP-A-3-249384 JP 2001-47493 A

  As described above, currently the mainstream antifouling paint agents use heavy metals such as organic tin, cuprous oxide, silver, lead, zinc, and inorganic tin as poisons for killing aquatic organisms. Since these paints are self-polished by the navigation of the ship and the metal components are eluted, they accumulate in the environment such as harbors and routes, and are now taken up as a serious environmental pollution problem. In particular, all ships coated with highly toxic organotin will be banned. In addition, the cuprous oxide system is also a serious problem of toxicity.

  In addition, workers who apply antifouling paints have been concerned about the adverse effects on health caused by these toxic substances. Furthermore, poor workability has been pointed out due to the problem of specific gravity of cuprous oxide (specific gravity 9.7). For this reason, ship officials are eagerly expecting the appearance of hazardous heavy metal-free antifouling resin agents and antifouling paint agents.

  The inventor of the present invention has long sought to develop and commercialize antifouling resin agents and antifouling paint agents based on awareness of these problems, and an antifouling effect resin obtained by kneading a high concentration of allophane with a resin / pigment. Has filed a patent on the drug. On the extension of this research and practical application experiment, an antifouling paint agent in which fine particles of silica and alumina were kneaded with resin / pigment was prototyped and a practical test using the following ships was conducted.

  As a result of conducting a comparative test including the actual navigation of the conventional paint of the type that kills aquatic organisms biochemically with cuprous oxide as a toxic substance, the antifouling resin agent and the antifouling paint agent of the present invention, The antifouling paint agent according to the present invention obtained remarkable practical good results as compared with the conventional antifouling paint agent. That is, in the conventional antifouling paint agent, shellfish and algae are surely killed, but they are killed while attached to the surface layer and the ship bottom. Even if the sample is washed with water, these dead aquatic organisms will not be detached from the sample. It is in a situation where it adheres to the paint more firmly because it died. In order to peel them off, the mechanical peeling action of a scraper or the like must be relied upon.

  On the other hand, in the sample to which the antifouling resin agent according to the present invention was applied, although some aquatic organisms were attached, they were all alive, and easily peeled off when the sample was washed with water. It has been experimentally proved that the antifouling resin agent and the antifouling coating agent according to the present invention have an excellent ability to prevent the adhesion of aquatic organisms compared to conventional antifouling agents.

  Such an antifouling resin agent and an antifouling coating agent according to the present invention are considered to be based on the following principle. That is, the spores of aquatic organisms floating in water are made of protein, and since the isoelectric point in water is on the acidic side, it has a negative potential in water. On the other hand, silica fine particles, which are functional materials for the antifouling resin agent and antifouling coating agent according to the present invention, have a negative surface potential, so the repulsion effect by ions between the spores of aquatic organisms is difficult to adhere to the paint surface. The condition to make is. That is, the repellent action against aquatic organisms is not derived from biochemistry but from electrochemistry. Moreover, it is thought that the effect | action which the synergistic effect by the antibacterial effect of an alumina microparticle brings about was effective.

  Embodiments for realizing the antifouling resin agent and antifouling coating agent according to the present invention as described above will be described below with reference to FIGS. 1 and 2.

  In order to maximize the underwater organism adhesion and antifungal action of the antifouling resin agent and antifouling coating agent according to the present invention, it is desirable to make the particle size of silica and alumina fine particles as small as possible, practically 1 μm. The following is preferable. Thus, the present invention is an antifouling resin agent and an antifouling paint agent based on a principle completely different from that of Patent Document 1.

  In the coating agent of Patent Document 1, silica is used in the form of silica sol. In this case, if the particle size of the silica fine particles is reduced to 1 μm or less, it becomes difficult for each fine particle to exist independently from other fine particles, and a large number of silica fine particles gather to form an infinite number of clusters. There is a nature. In a cluster state, it can only exhibit substantially the same effect as fine particles having a cluster particle size, and the silica particle method has a lower limit on the fine particle size. Therefore, in Patent Document 1, the practical limit of particle size is limited to 5 μm even if it is small.

  According to an experiment conducted by the inventor of the present invention, when the surface of a sample coated with an antifouling resin agent in which fine particles having a particle size of about 5 μm are applied is observed with an electron microscope, fine particles are not present as shown in FIG. The rules were only exposed in places, which resulted in a situation where aquatic organisms adhered to the mottles avoiding them. On the other hand, when a paint in which fine particles having a particle size of 1 μm or less are dispersed is observed with an electron microscope, a large number of fine particles are uniformly exposed on one surface as shown in FIG. I couldn't see it.

  When a ship kneaded with a structure kneaded with an antifouling resin agent and an antifouling paint agent according to the present invention, the surface of new fine particles is always exposed due to the physical wear phenomenon of submicron units due to water, and the initial underwater organisms The anti-adhesion action does not decay over time.

  The resin used in Example 1 is polybutadiene. This resin has obtained the best results in experiments with various samples. Compared with the most commonly used acrylic resin as an antifouling resin agent and antifouling paint agent, the antifouling resin agent and antifouling paint agent using hydroxylated polybutadiene have hydrophobicity and toughness and are extremely excellent. It showed durability and excellent overall results for the adhesion and prevention of aquatic organisms. The case where polybutadiene is used as the resin in Example 1 corresponds to claim 1 of the present invention.

  Antifouling resin agents and antifouling paint agents that use polybutadiene as a resin tend to be too elastic. It was judged that it was practically better to suppress this property somewhat and increase the rigidity. An antifouling resin agent and an antifouling coating agent excellent in practicality such as applicability were obtained by adding 10% to 20% melamine resin by weight to the polybutadiene. This is also an embodiment corresponding to claim 1 of the present invention.

  Waste ceramics, waste porcelain, rice husk ash, rice husk ash, wheat straw ash, and filtered diatomaceous earth, which are industrial wastes containing a large amount of silica, have properties equivalent to pure silica in effect. If these are pulverized to form fine particles containing 10% or more by weight of a component having a particle size of 1 μm or less, it is possible to obtain an underwater organism adhesion and prevention ability equivalent to that of claim 1 of the present invention. Such antifouling resin agent and antifouling coating agent correspond to claim 2 of the present invention. These raw materials are industrial waste, and according to this blending specification, industrial waste can be recycled, and the antifouling resin agent and antifouling paint agent according to the present invention are functionally highly compatible with the environment. In addition, there is a favorable effect that it becomes one solution of environmental problems in terms of raw materials used.

  In order to produce fine particles of 1 μm or less, a high level of technology is required, but at present, a technology that can be realized already exists. If the silica or alumina fine particles produced in this way are dispersed in the paint by a stirring action by a stirrer as in the conventional case, the fine particles are dispersed inhomogeneously and the desired performance cannot be exhibited. An effective dispersion method for introducing submicron-order fine particles into the best dispersion state, such as the antifouling resin agent and antifouling coating agent of the present invention, is diluted after kneading and dispersing each constituent fine particle at a high concentration. The master batch method.

  In the ingredients containing all solid fine particles and all resins in the raw material, the amount of diluted components is adjusted so that the state after kneading becomes a plastic clay or highly viscous paste, and a high degree of shear Mix well under the condition where force is applied to make a master batch, then add more diluted components and dilute and store homogeneously using a high-speed disperser, or add diluted components immediately before use to increase the speed. The technique of manufacturing a highly dispersed paint that disperses is heavily used as a masterbatch method.

  The masterbatch method is a useful dispersion method especially when fine particles of 1 μm or less are highly dispersed. By adding an appropriate dispersing aid, an excellent paste-like masterbatch that can withstand long-term storage can be obtained. It is done. If diluted and used, a long-term stable antifouling resin agent and antifouling coating agent can be obtained.

It is an electron micrograph of the sample surface of Example 1 when the particle size of the fine particles of silica and alumina is about 5 μm. It is an electron micrograph of the sample surface of Example 1 when the particle size of the fine particles of silica and alumina is 1 μm or less.

Explanation of symbols

1 Resin part of paint 2 Part of silica and alumina fine particles exposed on paint surface

Claims (3)

The main component of the resin is a polybutadiene hydroxide,
A combination of the above-mentioned resin and a coloring pigment added with a slight amount of melamine resin as a reinforcing material occupies a weight ratio of 20% to 50% of the solid weight excluding the weight of the solvent from the total weight,
When the residual solid weight is 100%, 10% or more by weight ratio of silica fine particles occupying 50% or more of them is 1 μm or less in particle size,
An antifouling resin agent and an antifouling coating agent comprising alumina fine particles containing a component having a particle size of 1 μm or less in a weight ratio of 10% or more.   The antifouling according to claim 1, wherein instead of silica fine particles, waste ceramics, waste porcelain, rice husk ash, rice husk ash, wheat straw ash, and diatomaceous earth used for filtration are used, which are industrial wastes containing silica in high concentration Resin agent and antifouling paint agent.   3. An antifouling resin agent and an antifouling paint agent according to claim 1 and 2, wherein the antibacterial resin agent and the antifouling coating agent are obtained by uniformly mixing silica, alumina or the like with the above-mentioned resin using a masterbatch method of kneading in a high concentration state .

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