JPH01190610A - Insecticidal and acaricidal composition in form of suspension in water - Google Patents

Abstract

PURPOSE:To obtain the title composition, consisting of crystallized Fenpropathrin(R), suspending and dispersing agent, thickener and water and having residual effects for a long period and further excellent in safety. CONSTITUTION:A composition consisting of (A) 1-60wt.% crystallized alpha- cyano-3-phenoxybenzyl 2,2,3,3-tetramethylcyclopropanecarboxylate(Fenpropathrin(R)) of >=98% purity obtained by a recrystallization method, (B) 0.1-10wt.% suspending and dispersing agent, such as polyoxyethylene phenyl ether or sorbitan ester of a fatty acid, (C) 0.05-20wt.% thickener (e.g., xanthan gum or CMC) for preventing settling of suspended particles and enhancing dispersion stability and (D) the remainder of water. The above-mentioned composition is prepared by a method for adding the ingredient (A) into an aqueous solution of the ingredient (B), placing the resultant mixture in a microglass bead peptizer, finely pulverizing the ingredient (A) and dispersing and suspending the resultant particles, etc.

Description

Detailed Description of the Invention <Industrial Application Field> The present invention is characterized in that it contains crystallized α-cyano-3-phenoxybenzyl °2,2,3.3-tetramethylcyclopropanecarboxylate. The present invention relates to an in-water M-turbid insecticidal/acaricidal composition having a long-term residual effect.

<Prior art> α-cyano-3-phenoxybenzyl 2,2°3.3
-Tetramethylcyclopropanecarboxylate (-ship name: Fenpropathrin) is obtained industrially with a purity of about 90%, and this industrial product is a viscous liquid at room temperature. An oil-in-water suspension insecticidal/acaricidal composition using this compound (hereinafter referred to as fenpropathrin) is described in JP-A-5[1)-49307, and is stable and conventional. It has been found that an oil-in-water suspension insecticidal and acaricidal composition can be obtained which has an efficacy as excellent as that of the formulations described above.

<Problems to be Solved by the Invention> Although the conventionally known oil-in-water suspension insecticidal/acaricidal compositions of fenpropathrin have excellent insecticidal/acaricidal effects, they The challenge was to improve the residual effect after it has been applied.

Means for Solving the Problems〉 As a result of various studies regarding these problems, the present inventors unexpectedly found that an aqueous suspension preparation using crystallized fenpropathrin has a long-term residual effect. The inventors have discovered an insecticidal and acaricidal composition that has the above-mentioned properties and also has excellent stability, leading to the present invention.

That is, in the present invention, crystallized fenpropathrin is
~60% by weight! A water-suspended insecticidal/acaricidal composition (hereinafter referred to as the composition of the present invention) having a long-term residual effect and comprising 0.1 to 10% by weight of a Q cloudy bone dispersant, a thickener, and residual water.
I will provide a.

Currently, commercially available fenpropathrin has low purity and is usually liquid or semi-solid.
When the content is 8% or more, it is easily crystallized and can be handled as a crystal. As a method for crystallizing fenpropathrin, a recrystallization method can be used to increase purity.

Suitable solvents for recrystallization include alcohols such as methanol and ethanol, aliphatic hydrocarbons such as hexane, cyclohexane, heptane, and methylcyclohexane, and aromatic solvents such as toluene and xylene. The melting point of this crystal is approximately 52°C.

In order to obtain the composition of the present invention using this, crystallized fenpropathrin is added to an aqueous suspending and dispersing agent solution, and this is placed in a micro glass peptizer to finely pulverize the crystallized fenpropathrin. There are methods such as dispersion and suspension. The size of the crystallized fenpropathrin particles suspended at this time varies depending on the stirring intensity, the type and amount of the suspending and dispersing agent, but can be adjusted within the range of approximately 1 μm to 200 μm in terms of particle size.

Finally, in order to prevent sedimentation of suspended particles and increase dispersion stability, if necessary, an aqueous solution of a thickener is mixed in an appropriate ratio to obtain a suspended insecticidal and acaricidal composition that is stable for a long time. .

Suspending and dispersing agents that can be used in the composition of the present invention include anionic, nonionic, cationic, amphoteric surfactants, such as fatty acid sulfate salts, higher alcohol sulfate salts, higher alcohol sulfonates, aryl sulfonate, alkylphenol type phosphate ester,
Alkylaryl sulfonate and its formalin condensate, polyoxyethylene alkylaryl sulfate, polyoxyethylene alkyl ether, polyoxyethylene phenyl ether, polyoxyethylene alkylaryl ether, polyoxyethylene phenylphenol derivative, polyoxyethylene sorbitan fatty acid ester , sorbitan fatty acid ester, etc. can be used. Among these surfactants, the more preferable ones are:
Examples include polyoxyethylene phenyl ether, polyoxyethylene alkylaryl ethers, polyoxyethylene sorbitan fatty acid ester, and sorbitan fatty acid ester.

Water-soluble polymers used in the present invention include natural water-soluble polymers such as gum arabic and pectic acid, semi-synthetic water-soluble polymers such as lignin sulfonate, cellulose sulfate, and carboxymethyl cellulose, polyvinyl alcohol, polyethylene oxide, Examples include synthetic water-soluble polymers such as polyvinylpyrrolidone, but among them polyvinyl alcohol with a degree of saponification of 70 to 90 mol% is preferred. Commercially available products include, for example, Gohsenol GL-05 (trade name of Nippon Gosei Kagaku Kogyo Co., Ltd.). , degree of saponification 86.5-89 mol%
), Gohsenol KL-05 (same, saponification degree 78.5 ~
81.5 mol%).

Examples of thickeners to improve dispersion stability include natural polyesters such as xanthan gum and locust bean gum, and semi-synthetic polyesters such as carboxymethyl cellulose. Synthetic polymers such as polyacrylic acid sodium salt, mineral fine powders such as magnesium aluminum silicate, etc. can be used alone or in combination of two or more. Commercially available thickeners include:
Ageli Seal T-101@ (Kao Atlas Co., Ltd. trade name, acrylic acid polymer), Ageli Seal FL-10
4FA @ (Kao Atlas Co., Ltd. trade name, xanthan gum derivative), Brimal ASE-60 @ (Japan Acrylic Co., Ltd. trade name, acrylic acid polymer), Rheosic 250H @ (Japan Pure Chemical Co., Ltd. trade name, sodium polyacrylate) , Carboball 0 (B, F, Gutudoritsuchi Chemical Company's product name, carboxyvinyl polymer), Kelzan@ (Kelco Vision of Merck Company's product name, xanthan gum derivative), Be-Gum@ (R,T, Pandelbilt) Company product name,
magnesium aluminum silicate), etc.

In addition, glycerin, ethylene glycol, propylene glycol, etc. may be added as an antifreeze agent in winter.
Inhibitors, antifungal agents, etc. can also be added. Various buffer solutions may be used in place of water for pHj.

In the composition of the present invention, the amount of crystallized fenpropathrin, suspending and dispersing agent, etc. added is not particularly limited, but usually the crystallized fenpropathrin is 1 to 60% by weight, and the suspending and dispersing agent is 0.1 to 60% by weight. Preferably, a range of 10% by weight is used. Further, the amount of the thickener added varies depending on the thickener, but is usually in the range of 0.05 to 20% by weight.

The pests to which the composition of the present invention can be applied include Lepidoptera such as the diamondback moth, Spodoptera spp., Aphids, and Leafminers; Hemiptera such as the whitefly and aphids; Thripsidae such as Southern melancholy thrips and Tea thrips; Leafminers, etc. Examples include Diptera such as Diptera, Hymenoptera such as turnip bugs, Coleoptera such as vegetable weevils and scarabids, Orthoptera such as crickets such as Grasshoppers, and Acari such as two-spotted spider mites, Kanzawa spider mites, orange spider mites, and apple spider mites.

The composition of the present invention can be used as an insecticide/acaricide that occurs in fields, greenhouses, orchards, etc.

The application amount of crystallized fenpropathrin, which is the active ingredient in the composition of the present invention, varies depending on weather conditions, target pests, etc., but is usually 10 to 1000 g per hectare. The composition of the invention is usually applied in a predetermined amount diluted with 100 to 100 liters of water per hectare.

In addition, the composition of the present invention can be applied as it is without any dilution, or after being diluted with 1 to 100 times water, it can be applied using an ultra-low volume (ULV) device or a micro-volume (LV) device.

<Effects of the Invention> According to the present invention, it is possible to obtain a water-suspended insecticide/acaricide containing fenpropathrin as an active ingredient, which has a residual effect over a long period of time.

<Examples> Next, the present invention will be explained in more detail by giving Examples, Comparative Examples, and Test Examples.

Example 1 547 g of fenpropathrin with a purity of 92.3% was placed in a 21 flask together with 1036 g of methanol and dissolved at 60°C. The mixture was cooled to 20°C, and about 0.1 g of crystals of fenpropathrin (purity: 99% or higher) was added, followed by stirring at the same temperature for 1 hour. The obtained crystals were filtered and washed with 500 cc of cold methanol. 195g of crystals obtained after vacuum drying, melting point 51.6°C1 purity 99.8
%Met. 200 g of the crystallized fenpropathrin drug substance obtained in this manner was added to 800 g of an aqueous solution containing 10% by weight of polyvinyl alcohol (trade name Gosenol GL-058, Nippon Gosei Co., Ltd.) as a suspending and dispersing agent, and 1500g of 1-1.5 glass peas
A stirrer with a stainless steel disk with a length of 50 cm and a diameter of 8 mm in the center of a stainless steel disk with a diameter of 50 m and a thickness of 5 cm, and an oval hole with a long axis of 20 m and a short axis of 1 O II 111. Place the stirrer (hereinafter referred to as stirring disk) on a three-one motor (Hayton type) and set the rotation speed to 2.
Mixed vigorously for 1.5 hours at 400 rpI11. Thereafter, the glass beads were filtered through a 60-mesh nylon net to obtain an M-in-water suspension. The particle size of fenpropathrin in the resulting suspension in water was approximately 2 μm. An aqueous thickener solution containing 0.4% by weight of xanthan gum and 0.8% by weight of magnesium aluminum silicate was added to 500g of the resulting suspension in water to adjust the total weight to 1000g.
A suspension type composition in water containing 10% by weight of fenpropathrin was obtained. [Present composition (1)] Comparative example 1 Liquid active substance of fenpropathrin (purity 92.3%) 1
Add 200 g of phenylxylylethane (trade name: Nisseki Hysol 5AS296 @, Nippon Oil Co., Ltd.) to 00 g to make a completely homogeneous solution. Next, this was added to 400 g of an aqueous solution containing 10% by weight of polyvinyl alcohol (trade name: GOHSENOL GL-05@, Nippon Gohsei Co., Ltd.) as an emulsifying dispersant, and stirred at room temperature until it became microscopic.
Then, using an autohomogen mixer (trade name of Tokushu Kika Kogyo Co., Ltd.), the mixture was stirred at 7000 rpm+* for 5 minutes. The average particle diameter of the resulting oil-in-water dispersion droplets was 2 μm.

To this, an aqueous thickener solution containing 0.4% by weight of xanthan gum and 0.8% by weight of magnesium luminium silicate was added to adjust the total weight to 1000g, and 10% by weight of fenpropathrin was added to the water-in-water solution. A type emulsion composition was obtained. [Comparative composition (1)] Comparative example 2 100% of the technical active ingredient of fenpropathrin (same as above)
g, 100 g of 5orpol 3005X (trade name of Toho Chemical Industry Co., Ltd., a mixture of nonionic surfactant and anionic surfactant) as an emulsifier and 800 g of xylene.
was added to obtain an emulsion containing 10% fenpropathrin.

[Comparative composition (2)] Trial test example This composition (1), comparative compositions (1) and (2) were diluted 2000 times with water,
A sufficient amount was applied using a small household sprayer. Collect treated leaves on the day of treatment and on a regular day after treatment, and place 3.4 instar Spodoptera larvae (Gundanwang) in a 9cm diameter cup.
a) Ten animals were put together and the mortality rate after 48 hours was determined. The results were as shown in FIG. 1, and the present composition (1) clearly showed a longer residual effect than the comparative compositions (1) and (2).

[Brief explanation of the drawing]

FIG. 1 is a graph showing the residual efficacy of the test sample in Test Example 1 against Spodoptera larvae. The vertical axis shows the mortality rate of Spodoptera larvae, and the horizontal axis shows the number of days that have passed since the drug treatment.

Claims (2)

[Claims] (1) 1 to 60% by weight of crystallized α-cyano-3-phenoxybenzyl 2,2,3,3-tetramethylcyclopropanecarboxylate and 0.1 to 10% by weight of a suspending and dispersing agent.
% by weight, a thickener, and a residual water content. (2) An insecticidal/acaricide method with long-term residual effect, which comprises applying the composition of claim 1.