JPH0561092B2 - - Google Patents

Description

[Detailed description of the invention]

(Field of Industrial Application) The present invention relates to a method for preventing marine organisms from adhering to FRP (fiber-reinforced plastic) products in the sea, which prevents shellfish, algae, etc. from adhering to FRP products. (Prior art) Conventionally, organic tin-based paints (tributyltin or triphenyltin-based paints) have been widely used as a method to prevent marine organisms from adhering to the water. Due to the strong pollution, in recent years it has been subject to regulations to prevent pollution and cannot be used continuously. Therefore, as an alternative non-polluting antifouling agent, we have developed an antifouling agent using copper-nickel alloy, taking advantage of the fact that it has been known empirically that marine organisms do not adhere to cupora nickel (copper-nickel alloy). By applying this as an antifouling layer using FRP (fiber reinforced plastic) gel coating method,
It is known to try to prevent marine organisms from adhering to marine structures (for example, Japanese Patent Publication No. 57-501382).
(see publication). (Problems to be Solved by the Invention) An antifouling gel coat layer was provided by the method described in Japanese Patent Application Publication No. 57-501382 mentioned in the prior art section.
When samples of FRP boards or FRP pipes were actually immersed in the sea in Naoshima, Kagawa Prefecture, and Makiminato, Okinawa Prefecture, and the state of adhesion of marine life was observed, it was found that during the initial period (3 to 4 months)
After this, it was no different from immersing solid FRP boards in the sea, and after 6 months of immersion, on Naoshima, barnacles, mussels, oysters, Many sea creatures such as brown beetles and yalpuras were attached to the vessels, and in Makiminato, barnacles were attached to the vessels, making them unsatisfactory in terms of practicality. The reason why sea creatures do not adhere to copper or copper-based alloys, except for the initial period, is that sea creatures do not like the copper ions that dissolve into the water, and the presence of copper ions is the reason why sea creatures do not adhere to copper or copper-based alloys. This is said to work as a repellent, but if copper or copper alloy powder is simply hardened with unsaturated polyester resin, vinyl ester resin, or epoxy resin using a gel coating method, it will not work because these resins have good seawater resistance. , although copper ions are eluted into the water only for the first period,
This is because the concentration is low, and since the antifouling agent is hardened with a resin that has good seawater resistance, continuous elution of ions does not occur. In order to examine this from a different angle, we immersed a test piece cut out from a gel-coated FRP board in a certain amount of purified water and measured the copper ions in the water using an atomic absorption spectrometer. As shown in the figure, and as can be inferred from this figure 2, simple gel-coat products containing copper-nickel antifouling agents have a low level of copper ion concentration dissolved in water, and a low concentration of copper ions. The peak occurs in 2 to 3 months, and the concentration tends to decrease thereafter. This is because the unsaturated polyester resin used has good seawater resistance, so the resin wraps around the copper-nickel antifouling agent, making it less effective. This is thought to be due to the fact that copper ions cannot be dissolved over a long period of time. The unsaturated polyester resin used in this experiment was a soft orthophthalic acid polyester resin (manufactured by Hitachi Chemical Co., Ltd., PS
-15), and this result was obtained even though this is a resin that is relatively suitable for eluting additives among unsaturated polyester resins. In parallel with this, we also experimented with a gel-coated product using an epoxy resin (Epicoat 828, manufactured by Yuka Ciel Epoxy Co., Ltd.), but the results were worse than products using unsaturated polyester resin. In addition, the “remarkable level of effect” in Figure 2
is an antifouling paint using the same antifouling agent (Dainippon Paint Co., Ltd.).
Co., Ltd., MF-200) is applied to the FRP board (film thickness approx.
200μm) under the same conditions, and although a remarkable effect was obtained as a result of the underwater immersion test, the paint melted away in about 2 years, exposing the base, and the lifespan was shortened to 2 years. The problem was that it was short, as shown below. The present invention has been made in view of the above-mentioned problems of the conventional technology, and it increases the concentration of copper ions dissolved in water of copper or copper-based alloy contained in the gel coat layer, and further stabilizes the concentration of copper ions dissolved in water. It is possible to dissolve copper ions over a long period of time, making it possible to put it into practical use.
The purpose is to provide a method for preventing marine organisms from adhering to FRP products. (Means for Solving the Problems) In order to achieve the above object, the present inventors have repeatedly investigated various types of products, and have found that gel coating and antifouling agents are added to the gel coat layer containing copper or a copper-based alloy. By adding a specific water-soluble polymer material suitable for the gel coat layer, the seawater solubility of the gel coat layer is promoted, and the concentration of copper ions dissolved in water is increased.
Furthermore, it was discovered that copper ions can be leached out for a long period of time in a stable state, leading to the present invention. In other words, in the case of an FRP product containing copper as an antifouling agent in the gel coat layer, the method for preventing the adhesion of marine organisms of the present invention applies to a group consisting of cellulose, modified starch, gelatin, gum arabic, and locust bean gum in the gel coat layer. FRP containing one or more water-soluble polymer materials selected from the following, and a copper-based alloy as an antifouling agent in the gel coat layer.
In the case of a product, one or more water-soluble polymeric materials selected from the group consisting of cellulose, metrose, gelatin, gum arabic, and locust bean gum are added to the gel coat layer. As the matrix resin used for forming the gel coat layer, in order to improve the seawater solubility of the gel coat layer, a soft orthophthalic acid-based unsaturated polyester resin, which has relatively good seawater solubility among unsaturated polyester resins, is preferable. . In the present invention, cellulose is a derivative of cellulose that has been converted to hydroxyethyl cellulose and made water-soluble, modified starch is soluble starch obtained by oxidizing corn starch, and gum arabic is purified sap secreted from the trunk of the genus Acacia in the Fabaceae family. Locust bean gum is made by removing the outer skin of beans from the legume family that grows in the Mediterranean region and pulverizing them. Metrose is a type of methylcellulose, which is made by reacting cellulose with methyl chloride. (Example) Hereinafter, the content of the present invention will be explained with reference to Examples. Examples 1 to 6, Comparative Examples 1 to 7 Unsaturated polyester resin was used as a matrix resin, and copper powder as an antifouling agent and a water-soluble polymer material as an additive were mixed in the proportions shown in Table 1. FRP products of Examples 1 to 6 and Comparative Examples 1 to 7 each having a gel coat layer (approximately 800 μm thick) were prepared, and the resulting FRP products had gel coat properties (workability, good smooth surface). The adhesion prevention effect (copper ion concentration) was evaluated. The evaluation results are shown in Table-1. Examples 7 to 14, Comparative Examples 8 to 13 Unsaturated polyester resin was used as a matrix resin, and copper-nickel alloy powder as an antifouling agent and water-soluble polymer material as an additive were added in the proportions shown in Table 2. FRP products of Examples 7 to 14 and Comparative Examples 8 to 13 were created by blending to form a gel coat layer (approximately 800 μm thick), and the resulting FRP products were as follows:
The gel coat properties and adhesion prevention effect were evaluated in the same manner as above. The evaluation results are shown in Table-2. In addition, each of the examples in Table-1 and Table-2 above
When we measured the copper ion concentration on test pieces of FRP products, we found that, as shown in Figure 1, in particular, those that use copper as an antifouling agent contain cellulose derivatives (hydroxyethyl cellulose) as a water-soluble polymer material. In addition, those using copper-nickel alloy as an antifouling agent and those with locust bean gum and gum arabic added as water-soluble polymer materials obtained results close to the desired copper ion concentration. . In addition, FRP boards and FRP pipes treated with gel coat according to the examples in Tables 1 and 2 are being immersed in the sea at Toba, Mie Prefecture, and Hitachi Port, Ibaraki Prefecture, respectively, and are being observed, but after 6 months of immersion, At the time point, there was no adhesion of shellfish in Examples 10 and 11, and only slight adhesion in the other Examples. In addition, in the water-soluble polymers in Tables 1 and 2, the details of gum arabic powder are unknown, but gum arabic is processed to be used as an emulsifier, thickener, or stabilizer for foods (imported products used). Powdered candy is a starch processed product made from corn starch (using processed Japanese food products), and branched dextrin is obtained by heating starch in powder form, also known as roasted starch (Sanmatsu Kogyo Co., Ltd.) product used).

【table】

【table】

[Table] (Effects of the Invention) As is clear from Fig. 1, the present invention allows copper ions to dissolve into water more easily than the conventional product in which a copper or copper alloy antifouling agent is simply contained in the gel coat layer. As the concentration increases, the anti-fouling effect improves, and although the longevity of the antifouling effect is currently unclear, it is possible to make the gel coat layer itself at least thicker (about 2 mm) than conventional coated products. Therefore, a significant improvement in life can be expected. By using a soft orthophthalic acid-based unsaturated polyester resin as the matrix resin for forming the gel coat layer, the solubility of the gel coat layer in seawater is improved, and the concentration of copper ions dissolved in water is increased, which helps prevent marine life from adhering to the gel coat layer. The effect is further improved.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the trends in copper ion concentration over time in Examples of the present invention, conventional products with gel coat layers containing an antifouling agent, and coated products. Second
The figure shows the level of dissolved copper ions and changes over time in a conventional gel coat layer using an unsaturated polyester resin as a matrix resin and a copper-nickel alloy as an antifouling agent.

Claims (1)

[Claims] 1. Formed with a gel coat layer containing copper
The method for preventing marine organisms from adhering to FRP products is characterized in that one or more water-soluble polymeric materials selected from the group consisting of cellulose, modified starch, gelatin, gum arabic, and locust bean gum are added to the gel coat layer. Law to prevent marine organisms from adhering to FRP products. 2. In the method for preventing marine organisms from adhering to FRP products formed with a gel coat layer containing a copper-based alloy,
Cellulose, Metrose,
A method for preventing marine organisms from adhering to FRP products, which is characterized by adding one or more water-soluble polymeric materials selected from the group consisting of gelatin, gum arabic, and locust bean gum. 3. The method for preventing marine organisms from adhering to FRP products according to claim 1 or 2, wherein the matrix resin for forming the gel coat layer is a soft orthophthalic acid-based unsaturated polyester resin.