JPS6317041B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel aquatic pest control agent containing a zinc salt of 2-mercaptobenzimidals as an active ingredient, or containing the zinc salt and an N-(chlorosubstituted phenyl)maleimide as an active ingredient. . In recent years, there has been a significant decline in Japan's marine resources due to the global 200 nautical mile problem, etc., and as a result, there has been a shift from fisheries that collect fish, such as aquaculture and young fish along the Japanese coast, to fisheries that raise them, and this has been commercially successful in various regions. Research for this purpose is being actively conducted in various fields. Such aquaculture is a major research topic in the fisheries industry, and the development of necessary fishing gear and the control of attached organisms on fishing nets are also important issues. Animal marine organisms such as barnacles, oysters, mussels, snails, sea squirts, hydrozoans, and plant marine organisms such as green laver and sea lettuce grow attached to fishing nets and ropes set in the sea, causing fishing nets, etc. It is well known that it pollutes. When these marine organisms breed, they clog fishing nets and reduce the flow of seawater, causing a lack of oxygen to fish and inhibiting their growth, causing damage such as facilitating the emergence of parasites. In addition, the durability of the fishing net may be reduced. For this reason, it is necessary to constantly remove attached organisms from fishing nets, etc., and the accompanying work of replacing fishing nets (aquaculture nets and fixed nets) requires a huge amount of time and expense, which has become a major problem in the fishing industry. Furthermore, the above-mentioned aquatic pests also adhere to and breed in places that are in constant contact with seawater or fresh water, such as the bottom of ships, underwater equipment such as buoys, underwater equipment of dams, and cooling water intake equipment. This can cause undesirable damage to the ship's bottom and equipment. Conventionally, in order to prevent the attachment and propagation of these aquatic pests, for example, heavy metal compounds such as cuprous oxide, mercury oxide, organic acid copper, and organic tin compounds, and organic chlorine compounds such as DDT and PCP have been used as control agents. has been used as. Also, recently, N-
It has been proposed to use N-arylmaleimides such as (2,4,6-trichlorophenyl)maleimide as an aquatic organism repellent (Japanese Patent Application Laid-Open No. 53-1971).
-Refer to Publication No. 9320). However, some of these conventionally used drugs are toxic to warm-blooded animals and fish, and some are accumulative and pollute the environment. Furthermore, some conventional drugs are only effective against specific aquatic pests, such as inorganic copper compounds that have little effect on algae. The present inventor conducted a search for a large number of compounds in order to develop an effective aquatic pest control agent that does not have the above-mentioned drawbacks, and as a result, discovered a 2-mercaptobenzimidazole zinc salt, a 2-mercaptobenzimidazole zinc salt, this compound, and an N-(chloro-substituted phenyl) compound. The inventors have discovered that a mixture of maleimides is suitable for the purpose and have arrived at the present invention. That is, the purpose of the present invention is to provide a control agent effective against a wide range of aquatic pests that is harmless to warm-blooded animals and fish and does not pollute the environment, and the gist thereof is as follows. (1) General formula below (In the formula, R represents a hydrogen atom or lower alkyl.) An aquatic pest control agent containing a 2-mercaptobenzimidazole zinc salt as an active ingredient. (2) General formula below (In the formula, R represents a hydrogen atom or a lower alkyl group.) A 2-mercaptobenzimidazole zinc salt represented by the following general formula: (In the formula, n represents an integer of 1 to 3.) An aquatic pest control agent containing N-(chlorosubstituted phenyl)maleimides as an active ingredient. There is no known example of using a 2-mercaptobenzimidazole zinc salt or a mixture thereof with an N-(chlorosubstituted phenyl)maleimide for controlling aquatic pests. When the pesticidal agent according to the present invention is used, it significantly inhibits the propagation of algae and insects, especially bulrushes, hydrozoans, barnacles, etc., without harming warm-blooded animals or fish, and without polluting the environment. These aquatic pests can be effectively controlled. The active ingredient in the present invention is a known 2-mercaptobenzimidazole zinc salt represented by the following formula. (In the formula, R represents a hydrogen atom or a lower alkyl group.) Preferred specific examples include 2-mercaptobenzimidazole zinc salt, 2-mercapto-4-
Examples include methylbenzimidazole zinc salt and 2-mercapto-6-methylbenzimidazole zinc salt, with 2-mercaptobenzimidazole zinc salt being particularly preferred. None of these zinc salts exhibits a fixed melting point and has a decomposition point of 270°C or higher. Other active ingredients are N-(chloro-substituted phenyl)maleimides represented by the following general formula. (In the formula, n represents an integer of 1 to 3.) Specifically, N-(2-chlorophenyl)maleimide (melting point 72-75°C), N-(3,5-dichlorophenyl)maleimide (melting point 139-140°C) ), N-
Examples include (2,4,6-trichlorophenyl)maleimide (melting point 130 to 132°C), and N-(2,4,6-trichlorophenyl)maleimide is particularly preferred. 2-mercaptobenzimidazole zinc salt alone and this and N-
A mixture with (chlor-substituted phenyl)maleimide has the effect of killing Chlorella (algae) and Artemia (crustacea), as shown by the results of the control power test described below, and further inhibits their growth and reproduction. It has the effect of According to this result,
It can be seen that the above-mentioned zinc salt and the above-mentioned mixture, which are the active ingredients of the present invention, exert a controlling effect on a wide range of aquatic pests including algae and insects. N-(chloro-substituted phenyl)maleimides are
According to the inventor's experiments, although it is effective in controlling algae, it is not necessarily sufficiently effective in controlling insects. Since it is mainly insects that adhere to fishing nets, the above maleimides alone cannot be expected to have a sufficient antifouling effect on fishing nets, but a mixture of this maleimide and a 2-mercaptobenzimidazole zinc salt is effective against insects. Therefore, the mixture exhibits an excellent antifouling effect on fishing nets. The aquatic pest control agent of the present invention contains 100% 2-mercaptobenzimidazole zinc salt, or 100% a mixture of 2-mercaptobenzimidazole zinc salt and N-(chlorosubstituted phenyl)maleimide. However, it is usually used in the form of a paint, emulsion, solution, etc. What form should it take?
It can be determined reasonably and appropriately depending on the object to which the pest control agent is applied and the place where it is applied. For example, when applied to fishing nets, the active ingredient and resin are dissolved in a solvent to form a resin solution. In this case, if necessary, for example, a plasticizer or the like may be added. Impregnate fishing nets with this substance and dry. The resin used here is
It may be either natural or synthetic, and preferably 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, and acrylic resin. In addition, as a solvent, benzene,
Examples include aromatic hydrocarbons such as toluene and xylene, aliphatic hydrocarbons such as kerosene and kerosene, alcohols, ketones, and organic acid esters. 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 with a known film-forming agent or solvent. The content of the active ingredient in the pesticidal agent of the present invention is:
Although it varies depending on the dosage form and the degree of control required, it is usually about 10 to 30% by weight based on the agent. When the active ingredient is a mixture of zinc salt and maleimide, the blending ratio of the two can be determined as appropriate from a practical standpoint, but preferably the zinc salt and maleimide are contained in approximately equal amounts. Next, the results of an algagicidal and insecticidal test on 2-mercaptobenzimidazole zinc salt, which is the active ingredient in the present invention, and a mixture of this salt and N-(2,4,6-trichlorophenyl)maleimide are illustrated. do. Test example 1 Chlorella scale method Ulva, Ulva, etc. are plants that attach to fishing net materials in the sea.
Since green algae such as blue laver are found in large numbers, we conducted a test to test their control power using chlorella, which belongs to the same species as green algae. Chlorella culture solution (PH5.4) as shown below
The active ingredient drug of the present invention is added to 200 ml at a 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 algicidal concentration. The culture solution composition is as follows. K NO 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] The control is a chemical specified for antifouling ship bottom paint. Test example 2 Artemia scale method Many types of crustaceans, such as barnacles, bryozoans, hydrozoans, lizards, and sea squirts, are known to attach to underwater fishing net materials. Brine shrimp (scientific name: Artemia) belongs to the same crustacean as barnacles.
A test was conducted to test the control power of the active ingredient of the present invention using Salina (Artemia Salina). Commercially available brine shrimp dried eggs were mixed with artificial seawater (PH
8.3) Add 0.2g to 500ml and keep at around 25℃ 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, leave it at a constant temperature of 20°C, and determine the lethal dose after 24 hours. The results are shown in Table 2.

[Table] The control is a chemical specified for antifouling ship bottom paint. * Median Tolerance Limit (50% lethal dose) Test Example 3 Chlorella Scale Method A test was conducted using the method shown in Test Example 1 above.

【table】 Test example 4 artemia scale method A test was conducted using the method shown in Test Example 2 above.

[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. (1) A polyethylene fishing net was immersed in the aquatic pest control agent of the present invention to allow the agent to sufficiently adhere to the surface of the net, and then dried. The fishing net treated in this way was cut into square pieces with a side length of 500 mm, which was fixed to a square frame with a side length of 450 mm made of 18 mm diameter PVC resin pipes, and then hung to a depth of 1 m below the sea surface. was 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 three-month period. The results were as shown in Table 5.

[Table] The symbols in the table indicate the adhesion status of contaminant organisms. Contaminant organisms are so heavily attached that it becomes unusable. + Significant amount of contaminant organisms. ± Slight amount of contaminant organisms attached. - No contaminating organisms. Table 5 shows that even after 3 months, no or only a small amount of contaminant organisms adhered to the fishing net pieces treated with the formulation of the example of the present invention; In some cases, it has been shown that a significant amount of contaminant organisms has already adhered after one month. According to these results, the formulations of Examples 1 and 2 of the present invention are highly effective in preventing contaminant organisms from adhering to fishing nets, and furthermore, the control agents of the present invention are excellent in controlling aquatic pests. Recognize. (2) A similar test was conducted using a piece of iron instead of the piece of fishing net in (1) above, and applying the antifouling paint on the bottom of the boat prepared in Example 3 to the piece. The result is the 6th
It was as shown in the table.

[Table] The symbols in the table are the same as in Table 5. According to the results in Table 6, it can be seen that the paint of Example 3 of the present invention has a remarkable effect on preventing the attachment of contaminant organisms to the bottom of a ship, and is excellent in controlling aquatic pests.

Claims (1)

[Claims] 1. The following general formula (In the formula, R represents a hydrogen atom or a lower alkyl group.) An aquatic pest control agent containing a 2-mercaptobenzimidazole zinc salt as an active ingredient. 2 General formula below (In the formula, R represents a hydrogen atom or a lower alkyl group.) A 2-mercaptobenzimidazole zinc salt represented by the following general formula: (In the formula, n represents an integer of 1 to 3.) An aquatic pest control agent containing N-(chlorosubstituted phenyl)maleimides as an active ingredient.