JPS6320803B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel oil-in-water suspension insecticidal and acaricidal composition, and more specifically, a hydrophobic liquid insecticidal and acaricidal component containing α-cyano-3-phenoxybenzyl (+)-2- (4-chlorophenyl)isovalerate (hereinafter referred to as fenvalerate A)
It is called. ), or (-)-α-cyano-3-phenoxybenzyl (+)-2-(4-chlorophenyl)isovalerate and (+)-α-cyano-3
-Enantiomer pair with phenoxybenzyl (-)-2-(4-chlorophenyl)isovalerate (hereinafter referred to as
It is called Fuenvalerate Y. ) containing 60-95% α-cyano-3-phenoxybenzyl 2-(4
- 1 to 50% by weight of (chlorophenyl)isovalerate, polyvinyl alcohol or gum arabic 2
This invention relates to a novel oil-in-water suspension insecticidal and acaricidal composition that is stable and has superior efficacy comparable to conventional formulations, consisting of ~10% by weight, an appropriate amount of thickener, and residual water. . Among the conventional pesticide formulations that are sprayed in liquid form, emulsions generally consist of a pesticide active ingredient, a synthetic surfactant, and a large amount of organic solvent. They often have drawbacks such as toxicity and irritation to plants and phytotoxicity to crops. On the other hand, powdered wettable powders are available as formulations that do not use organic solvents.
The fine powder scatters and is inconvenient to handle, and the high concentration and small amount of air spraying (300 ml per 10 ares)
There are undeniable drawbacks such as the possibility of lower than ml (ml or less). For the above reasons, pesticide suspension compositions and aqueous emulsions in which hydrophobic pesticide ingredients are suspended and dispersed in fine particles using water as a base instead of organic solvents, powder carriers, etc. have been studied. . Since this type of composition is handled as a liquid, it does not generate dust when preparing the spray solution, and it is easy to handle quantitatively like a conventional liquid formulation. There are fewer problems with chemical damage to crops. However, in the suspension pesticide compositions that have been proposed so far, the hydrophobic pesticide active ingredient, which is the active ingredient, is mainly in solid form (Japanese Patent Application Laid-open No. 126635/1983,
JP-A-50-76236, JP-A-52-148625, U.S. Patent No. 4,071,617, etc.), oil-in-water type oil-in-water products using oily base materials generally have long-term stabilization of physical properties. It is considered difficult and has not been put into practical use. On the other hand, as an oil-in-water type agricultural chemical composition,
Publication No. 20520, Japanese Patent Application Laid-Open No. 1983-54547, Japanese Patent Application Publication No. 1972
There are aqueous emulsions such as those disclosed in Publication No. 122628, but these are solubilized types that use a large amount of general-purpose synthetic surfactants to reduce the particle size of the active ingredient to 0.1 μm or less, and have a large amount of interfacial Disadvantages such as high cost and toxicity due to the use of active agents have not been solved. The present inventors investigated the formulation of the hydrophobic liquid insecticidal and acaricidal compounds in order to compensate for the drawbacks of the conventional formulations as described above, and as part of this study, a water-soluble polymer was used as a suspension aid. Various studies have been conducted on oil-in-water compositions. As a result, it was discovered that among various water-soluble polymers, polyvinyl alcohol or gum arabic was most suitable as a suspension aid for the above-mentioned hydrophobic liquid insecticidal and acaricidal compounds. After further investigation, we have completed the present invention. That is, the present invention uses α-cyano-3-phenoxybenzyl 2-(4-chlorophenyl)isovalerate containing 60 to 95% of fenvalerate A or fenvalerate Y as a hydrophobic liquid insecticide and acaricide component. 50% by weight, more preferably 1-40% by weight, polyvinyl alcohol or gum arabic 2
A new formulation consisting of ~10% by weight, an appropriate amount of thickener, and residual water, whose chemical and physical properties are stable over a long period of time, and which is as effective as conventional insecticidal and acaricidal formulations. provides a composition;
According to the present invention, organic solvents and synthetic surfactants that have been widely used in conventional formulations, such as higher alcohol sulfate salts, higher alcohol sulfonate salts, alkyl sulfonate salts, aryl sulfonate salts, and alkylaryl sulfonic acids The above hydrophobic liquid can be produced without using salts and their formalin condensates, fatty acid ester compounds, polyoxyethylene alkyl ethers, polyoxyethylene alkylaryl ethers, polyoxyethylene phenylphenol derivatives, polyoxyethylene sorbitan alkylate, etc. A simple operation of mechanically dispersing and suspending an insecticidal or acaricidal compound in the form of fine particles in an aqueous solution of polyvinyl alcohol or gum arabic, and then stabilizing the fine particles by adding a suitable thickener, An insecticidal and acaricidal composition that is stable, highly effective, safe and easy to handle can be obtained at low cost. Next, an outline of the manufacturing process of the composition of the present invention will be described. First, a predetermined amount of the above-mentioned hydrophobic liquid insecticidal and acaricidal compound is added to a 2-20% by weight aqueous solution of polyvinyl alcohol or gum arabic, heated to 60-70°C, and heated using a conventional stirrer, such as a TK homomixer (Tokushu Kikaku Co., Ltd.). Disperse and suspend using a Shinagawa multi-purpose mixer (trade name of Sanei Seisakusho) or the like (trade name of Kogyo Co., Ltd.). The size of the suspended insecticidal and acaricidal oil droplets can be adjusted within the range of about 1μ to 200μ by changing the stirring intensity and the amount of polyvinyl alcohol or gum arabic added. be. Finally, in order to prevent sedimentation of suspended particles and increase dispersion stability, an aqueous solution of a thickener is mixed in an appropriate proportion to obtain a suspended insecticidal and acaricidal composition that is stable for a long time. Fuenvalerate Y in the present invention is 60 to 95%
α-Cyano-3-phenoxybenzyl 2-
(4-chlorophenyl)isovalerate is published by JP-A-Sho.
It can be easily obtained by the method disclosed in Japanese Patent No. 54-103831. In addition, in the present invention, polyvinyl alcohol with a degree of polymerization of 1500 or less and a degree of saponification of 70 to 90 mol% is suitable, such as Gohsenol GL.
-05 (trade name of Nippon Gosei Kagaku Kogyo Co., Ltd., degree of polymerization 1000 or less, degree of saponification 86.5 to 89 mol%) is used. Examples of thickeners include gum tragacanth,
Guar gum, sodium alginate, sodium carboxymethyl cellulose, sodium carboxymethyl starch, hydroxyethyl cellulose, methyl cellulose, polyacrylic acid and derivatives thereof can be used, and specific examples include commercially available Agrisol FL-100F and Agrisol FL-
104FA (product name of Kao Atlas Co., Ltd.), Primal ASE-60 (product name of Nippon Acrylic Co., Ltd.), Rheozik 250H (product name of Nippon Pure Chemical Co., Ltd.), Carbopol (product name of B, F, Gutsudoritsuchi Chemical Company) , Kerzan (trade name of Kelco Division of Merck Company), Begum (trade name of RT Vanderbilt Company), etc. The amount of these thickeners to be added is in the range of 0.1 to 20% by weight, but the optimum amount to be added differs depending on each thickener. The oil-in-water suspension insecticidal and acaricidal composition of the present invention obtained as described above does not use any organic solvent, so it has no flammability, bad smell of solvent, human hoarding, toxicity to small animals, irritation, etc. It is convenient in that there is no concern about chemical damage to crops, it has good dilutability with water when preparing the spray solution, and it is easy to handle quantitatively like conventional liquid preparations. Next, the present invention will be explained in more detail using reference examples and examples. Reference Example 1 180 g of a 2% by weight aqueous solution of albumin, cellulose sulfate derivative, sodium alginate, carrageenan, polyvinylpyrrolidone, carboxymethyl cellulose, sodium lignin sulfonate, gelatin, gum arabic, and Gohsenol GL-05 were each added with the hydrophobic substances listed in Table 1 below. Add 20g each of liquid insecticidal and acaricidal ingredients and disperse with a TK homomixer while heating at 70℃ so that oil droplets of insecticidal and acaricidal ingredients have a particle diameter of 1 to 100μ (observed with a microscope). After that, each was sealed in an airtight glass container and heated to 60℃.
for 24 hours, and the dispersion stability of the insecticidal and acaricidal ingredients was observed. Note that the dispersion stability evaluation criteria are as follows. 〇……No coalescence of oil droplet particles is observed. △...Coalescence of oil droplet particles is observed, but separation as an oil layer is not observed. ×...Oil droplet particles coalesce and separate as an oil layer. The results are shown in Table 1.

[Table] Examples 1 to 5 A predetermined amount of Fuenvalerate A was added to an aqueous solution of Gohsenol GL-05 listed in the table below, and the mixture was heated at 70°C.
The mixture was stirred for 5 minutes in a TK homomixer under heating. Furthermore, at room temperature, agrisol listed in the table below
Add the neutralized aqueous solution of FL-100F and wait for a few minutes.
After mixing with gentle agitation, 100 g of oil-in-water suspension formulations of each concentration were obtained.

[Table] Example 6 In Example 4, Gohsenol GL-05
A 10% aqueous solution of gum arabic was used instead of a 10% aqueous solution, and Rheozic 250H was used instead of a neutralized 25% aqueous solution of Agrisol FL-100.
100 g of an oil-in-water suspension preparation with an active ingredient concentration of 20% by weight was obtained in exactly the same manner as in Example 4, except that a 1% aqueous solution of . The particle size range was 1μ to 70μ. Example 7 In Example 2, the procedure was completely the same as in Example 2 except that α-cyano 3-phenoxybenzyl 2-(4-chlorophenyl)isovalerate containing 80% of fenvalerate Y was used instead of fenvalerate A. In the same manner, 100 g of an oil-in-water suspension preparation was obtained. The particle size range was 1μ to 50μ. Example 8 In Example 4, the procedure was completely the same as in Example 4 except that α-cyano 3-phenoxybenzyl 2-(4-chlorophenyl)isovalerate containing 80% of fenvalerate Y was used instead of fenvalerate A. In the same manner, 100 g of an oil-in-water suspension preparation was obtained.
The particle size range was 1μ to 40μ. Example 9 In Example 6, α-cyano-containing 80% of fuenvalerate Y instead of fuenvalerate A was used.
100 g of an oil-in-water suspension was obtained in exactly the same manner as in Example 6, except that 3-phenoxybenzyl 2-(4-chlorophenyl) isovalerate was used.
The particle size range was 1μ to 80μ. Example 10 The stability of the composition of the present invention was tested using the compositions obtained in Examples 2 and 7. Table 2 shows the results.
Shown below.

【table】

[Table] *Values based on content analysis values during preparation As is clear from the above table, the composition of the present invention is extremely stable both chemically and physically. Example 11 Two oil-in-water suspension preparations obtained in Example 4 and Example 8 (hereinafter referred to as Composition 4, Composition 4, respectively)
It is called 8. ) and two 20% by weight emulsions each containing the same insecticidal and acaricidal ingredients as these oil-in-water suspension formulations (the emulsifiers are a polyoxyethylene styrenated phenyl ether nonionic surfactant and dodecylbenzenesulfonic acid). A mixture of calcium salts (referred to as control formulations 4 and 8, respectively) at a predetermined concentration was sprayed on Chinese cabbage seedlings at a rate of 30 ml/2 pots on a turntable, and after air-drying, the leaves were cut into polycups. The 3rd to 4th instar larvae of Spodoptera were released in groups of 10, and the mortality rate on the second day was determined. The results are shown in Table 3.

[Table] As shown in the table above, it was confirmed that the composition of the present invention exhibited the same excellent efficacy as the control formulation at any dilution ratio. Example 12 The surfaces of tangerine leaves were brought into close contact with absorbent cotton moistened with water, and 20 adult female tangerine spider mites were each released on the undersides of the tangerine leaves. Present compositions 4 and 8 and control preparations 4 and 8 were diluted with water to make 500 ppm solutions, and 8 cc of the solutions were sprayed on tangerine leaves, respectively. After 24 hours, the number of surviving insects was counted and the average mortality rate of each three replicates was determined. The results are shown in Table 4.

[Table] As shown in the table above, it was confirmed that the composition of the present invention exhibited the same excellent efficacy as the control formulation. Example 13 Regarding the mucous membrane irritation of the composition of the present invention, composition 4 of the present invention
and 8 using EPA guidelines [Federal
Register, 43, 37359-37360 (1978)]. At the same time, similar tests were conducted on Control Preparations 4 and 8 for comparative study. The experimental results are shown in Table 5, and the stimulus response intensity and maximum total score of stimulus intensity in the table are values obtained according to the stimulus response criteria in Table 6.

【table】

【table】

【table】

[Table] As is clear from Table 5, when comparing the intensity of stimulation response and the maximum total score of stimulation intensity for the composition of the present invention and the control formulation, the oil-in-water suspension formulation of the present invention is better than the control formulation. The degree of irritation is mild. Example 14 A group of 10 male and female mice (DD strain) was given diluted solutions of Compositions 4 and 8 and Control Preparations 4 and 8 (diluted with distilled water) per 1 kg of body weight per mouse.
After oral administration at a rate of 20 ml, the number of dead animals was observed for 2 weeks, and the method of Litchfield and Wilcoxon (J.
Pharmacol. Exptl. Therp., 96.99 (1949)). The results are shown in Table 7, and as is clear from the results, the composition of the present invention has a significantly lower degree of acute oral toxicity than the control formulation.

【table】

Claims (1)

[Claims] 1 α-cyano-3-phenoxybenzyl (+)-2-(4-
chlorophenyl)isovalerate or (-)-
α-cyano-3-phenoxybenzyl (+)-
2-(4-chlorophenyl)isovalerate and (+)-α-cyano-3-phenoxybenzyl
α-cyano-3- containing 60-95% of the enantiomer pair with (-)-2-(4-chlorophenyl)isovalerate
Phenoxybenzyl 2-(4-chlorophenyl)
An oil-in-water suspension insecticidal and acaricidal composition comprising 1 to 50% by weight of isovalerate, 2 to 10% by weight of polyvinyl alcohol or gum arabic, an appropriate amount of a thickener, and residual water.