JPS6124365B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a seawater pest control agent that has excellent control effects and safety. Animal marine organisms such as barnacles, oysters, mussels, scallops, sea squirts, and plant marine organisms such as sea lettuce and blue seaweed cannot contaminate fishing nets, etc. by breeding on fishing nets, ropes, etc. set in the sea. This is well known. When these marine organisms breed, they clog fishing nets, obstructing the flow of seawater, causing oxygen deficiency in fish, inhibiting their growth, and causing damage such as facilitating the development of parasites. In addition, the durability of the fishing net may be reduced. Therefore, it is necessary to constantly remove attached organisms from fishing nets, etc., and the accompanying work to replace fishing nets (aquaculture nets and fixed nets) requires a huge amount of time and expense, which has become a major problem in fishing nets. Furthermore, shellfish and algae can adhere to and grow on the bottom of ships, underwater equipment such as buoys, cooling water intake equipment, and other areas that are in constant contact with seawater, causing undesirable conditions on these bottoms and equipment. . Conventionally, heavy metal compounds such as cuprous oxide, organic acid copper, and organic tin compounds have been used as antifouling agents to prevent the attachment and propagation of these marine pests. Although these agents have great antifouling power, they are toxic to warm-blooded animals and fish, and have a tendency to accumulate, making them undesirable from an environmental hygiene perspective. In view of the above circumstances, the present inventors have provided a control agent that has an excellent control effect, is harmless to warm-blooded animals and fish, does not cause environmental pollution, and is effective against a wide range of marine pests. As a result of extensive research aimed at achieving this goal, the present invention has been achieved. That is, the present invention has the following general formula: (However, in the formula, R represents a hydrogen atom, a chlorine atom, a lower alkyl group, or a lower alkoxy group, and Z represents an oxygen atom or a sulfur atom.) It is a pest control agent. Although the active ingredient quinoxaline compound in the present invention is known as a pesticide, it is not known to exhibit effective antifouling power against a wide range of marine pests. Next, typical examples of compounds used in the present invention will be shown. In addition to the melting point, include the name of the solvent used for recrystallization. Compound 1 Quinoxaline-2,3-dithiocarbonate melting point 182-183℃ (dioxane) Compound 2 6-Methylquinoxaline-2,3-dithiocarbonate Melting point 171-172℃ (Toluene) Compound 3 5-Methylquinoxaline-2,3-dithiocarbonate Melting point 134-135℃ (ligroin) Compound 4 6-Methoxyquinoxaline-2,3-dithiocarbonate Melting point 165-166℃ (dioxane) Compound 5 Quinoxaline-2,3-trithiocarbonate Melting point 169-170℃ (dioxane) Compound 6 6-Chlorquinoxaline-2,3-trithiocarbonate Melting point 171-172°C (methyl cellosolve) Compound 7 5-Methylquinoxaline-2,3-trithiocarbonate melting point 139-140°C (carbon tetrachloride-ligroin) In the present invention, one or more of these compounds can be contained. The quinoxaline compound, which is the active ingredient in the present invention, exhibits a pesticidal effect comparable to that of conventionally used pesticidal agents, and has extremely low toxicity to humans and fish compared to organometallic compounds. agents are extremely useful. The content of the quinoxaline compound in the agent of the present invention varies depending on the dosage form, degree of control requirements, etc., but is usually 10 to 40% by weight based on the agent. In the present invention, in addition to the quinoxaline compound, other active ingredients,
For example, tributyltin oxide, cuprous oxide, tetramethylthiuram disulfide, and dimethyldithiocarbamate zinc salt may be used together, but when metal compounds are used together, the amount used must be regulated in consideration of toxicity. There is. The marine pest control agent of the present invention is usually used in the form of a paint, emulsion, solution, or the like. The form of the antifouling agent can be rationally and appropriately determined depending on the object to which the antifouling agent is applied and the place where it is applied. For example, when used in fishing nets, the active ingredient is dissolved in a solvent together with resin and rubber to form a resin solution. In this case, for example, a plasticizer or the like may be added as necessary. Impregnate fishing nets with this substance and dry. The resin used here may be either natural or synthetic and has the effect of fixing the drug to the surface of the net and gradually dissolving the active ingredient into the water. Examples of such resins include rosin, ester gum, chlorinated rubber, vinyl chloride resin, vinyl acetate resin, acrylic resin, and alkyd resin. When applied to the bottom of a ship, the pesticidal agent of the present invention can be used in the form of a paint by mixing and dissolving the active ingredient of the present agent with a known film-forming agent or solvent. Next, algagicidal and insecticidal tests for the active ingredients will be shown. Algaecidal test (Chlorella scale method) Since green algae such as Ulva and Green algae are often seen as plants attached to fishing net materials in the sea, we conducted a test to test the control power using Chlorella, which belongs to the same species as these. Chlorella culture solution (PH
5.4) Add the active ingredient drug of the present invention to 200 ml at the specified concentration. A fixed amount of Chlorella Ellipsoida, which had been previously cultured, was added thereto, and aerated culture was carried out for 6 days at a constant temperature of 23° C. while providing illumination with a fluorescent lamp. After 6 days, 10 ml of the cultured Chlorella was placed in a centrifuge tube, centrifuged at 4000 rpm for 20 minutes, and the volumes were compared to determine the minimum growth-inhibiting concentration. The culture solution composition is as follows. KNO ₃ 5g KH ₂ PO ₄ 1.25g MgSO _{4.7H 2} O 2.5g FeSO _{4.7H 2} O 0.003g Glucose 15g Water 1 The results are shown in Table 1.

【table】

[Table] (Note) The control is a chemical specified for antifouling paint on the bottom of a ship. The circle indicates the agent of the present invention. Insecticidal test (Artemia scale method) Animals that adhere to underwater fishing net materials include barnacles, bryozoans, and hydrophiles. Although many types of crustaceans are known, such as snails, ascidians, and ascidians, we used brine shrimp (scientific name: Artemia Salina), which belongs to the same crustacean as barnacles, as an experimental material to obtain the active ingredient of the present invention. A test was conducted to determine the control power of the plant. Add 0.2 g of commercially available brine shrimp dried eggs to 500 ml of artificial seawater (PH8.3) and maintain at around 25°C while aerating with an air pump. After 1 to 2 days, the hatched larvae swim out. This was transferred to another artificial seawater and left in a constant temperature of 20℃ for 2 days with ventilation. Artemia individuals after 2 days are used in the test. Pipette the active ingredient of the present invention into 100 ml of artificial seawater to the specified concentration, and heat at 20°C.
Leave it at constant temperature, and after 24 hours, determine the 50% effective insecticidal concentration (minimum concentration required for 50% lethality). The results are shown in Table 2.

【table】

[Table] (Note) The control is a chemical specified for ship bottom antifouling paint. The circle mark is the agent of the present invention. According to the results of the algaecide test and the insecticide test,
It can be seen that the quinoxaline compounds of the present invention are significantly more effective than ship bottom paint agents in most cases. Next, examples of the present invention will be shown, but the present invention is not limited thereto. All blending ratios below are parts by weight. Examples 1 to 8 and Comparative Examples 1 and 2 Marine pest control agents were prepared by uniformly mixing and dispersing the following compositions using a disperser.

【table】

[Fishing net antifouling agent underwater immersion test]

In order to evaluate the effectiveness of the pesticidal agent according to the present invention, the following underwater immersion test was conducted. A polyethylene fishing net was immersed in the insect repellent obtained in the example, the agent was sufficiently attached to the surface of the net, and the net was dried. The fishing net treated in this way has a side length of 500 mm.
The fishing net pieces were cut into square pieces of 1.0 mm in diameter, fixed to a square frame with sides of 450 mm made from PVC resin pipes with a diameter of 18 mm, and suspended at a depth of 1 m below the sea surface, and the fishing net pieces were immersed in the sea. At the same time, untreated fishing nets were immersed in the sea in the same manner, and the degree of adhesion of seawater organisms to the nets was compared and observed monthly over a four-month period. The results were as shown in the table below.

【table】

[Table] Table 4 shows that in the case of fishing net pieces treated with the agent obtained in the examples of the present invention, no or only a small amount of contaminant organisms adhered even after 3 months; In case of processing, 1
It has been shown that a significant amount of contaminant organisms have already adhered after a month has passed. The results show that the agent of the present invention is highly effective in preventing contaminant organisms from adhering to fishing nets, and that the agent of the present invention is also excellent in controlling marine pests. Examples 9 to 17 and Comparative Examples 3 and 4 The following compositions were uniformly mixed and dispersed using a ball mill to prepare ship bottom antifouling paints.

[Sea bottom antifouling paint underwater immersion test]

In order to evaluate the effectiveness of the pesticidal agent according to the present invention, the following underwater immersion test was conducted. The anticorrosive agent obtained in the example was precoated with an anticorrosion paint, and after coating twice on a 200 x 400 x 2.3 mm mild steel plate, the plate was suspended at a depth of 1 m below the sea surface and subjected to an underwater immersion test. The attached area of living organisms was measured and expressed as a percentage of 100. Next, the test results are shown in the table below.

[Table] According to the results in Table 6, the test pieces treated with the agent obtained in the examples of the present invention prevented the attachment of marine harmful organisms over a long period of time, and were as effective as tin, which is currently considered the best. was recognized. As described above, the agent of the present invention has an excellent antifouling effect on ship bottoms, and in turn exhibits an outstanding effect on controlling marine pests.

Claims (1)

[Claims] 1. General formula (However, in the formula, R represents a hydrogen atom, a chlorine atom, a lower alkyl group, or a lower alkoxy group, and Z represents an oxygen atom or a sulfur atom.) It is characterized by containing a quinoxaline compound represented by the following as an active ingredient. Marine pest control agent.