JPH0759481B2 - Stable pesticide formulation in water - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to stable pesticide formulations in water.

More specifically, the present invention mixes a special surfactant and a heteropolysaccharide which is a water-soluble thickener to maintain a uniform dispersibility of a pesticide formulation in water for a long period of time, and to apply it at a normal concentration for ground spraying. Of course, it is also suitable for high-concentration spraying such as aviation spraying (ULV spraying, LV spraying and S spraying), and even in such high-concentration spraying, it can be mixed with other agricultural chemical emulsions and suspended in water. It provides pesticide formulations.

Pesticide formulation forms generally include powders, granules, wettable powders and emulsions. Among these, the dust has a drawback that it is often scattered to the surroundings during spraying. In addition, since the wettable powder is composed of fine particles, powdering during preparation of the spray liquid is severe, which causes a problem of affecting the human body. In addition, emulsions require that the drug substance be readily soluble in organic solvents, which limits the pesticide drug substance that can be emulsified and the risk of storage due to the use of organic solvents, and in some crops. It has drawbacks such as chemical damage.

Furthermore, recently, in order to save labor in the spraying work, air spraying with liquid agents (ULV spraying, LV spraying and S spraying) has become widespread, but conventional dosage forms are not always suitable for this. No, the development of new drug formulations is desired. As a suitable formulation for this, a spraying agent is known in which fine particles of a solid raw material which is poorly soluble or insoluble in water are formulated in a suspension form in water or a hydrophilic solvent by adding an emulsifier and a dispersant.

However, conventional suspension-type preparations have poor long-term physical stability, and in aerial spraying, which is a high-concentration spray, when mixed with other emulsions, agglomeration of suspended particles occurs, causing separation and sedimentation. Squeeze a helicopter strainer,
It has drawbacks such as the chemical damage caused by the agglomerates adhering to crops, and it does not have properties suitable for pesticide formulations in suspension.

JP-A-55-129201, JP-B-58-24401 and JP-A-58-124702 disclose the technology of a suspension-type agrochemical formulation, but it is described in JP-A-55-129201. In the formulation, the active ingredient sparingly water-soluble or water-insoluble pesticide does not sufficiently spread in water and does not suspend uniformly, and when used in combination with other pesticide emulsions, agglomerates are formed and the strainer is blocked. Cause.

The formulation described in Japanese Patent Publication No. 58-24401 has a drawback that the long-term storage stability is poor because the yield value is poor. Further, the formulation described in JP-A-58-124702 cannot be used as a mixture with other agricultural chemical emulsions. That is, in order to control pests that occur at the same time, a method of mixing and spraying with other pesticides is used as a labor-saving means in the field. Agglomerates of
This causes the strainer to jam.

The present inventors have conducted extensive studies to eliminate the above drawbacks, and as a result, by blending a special emulsifier and a heteropolysaccharide, a pesticide that is solid and sparingly water-soluble or water-insoluble at room temperature is uniformly and stably suspended in water. A pesticide formulation in suspension in water that is turbid, easy to handle, has excellent storage stability, dispersibility during spraying and excellent water suspension properties, is applicable to aerial spraying, and can be mixed with other pesticide emulsions. It was invented.

That is, the water-based pesticide formulation of the present invention is 50 wt% or less of one or more solid and sparingly water-soluble or water-insoluble pesticide at room temperature, polyoxyethylene alkylphenol ether
0.1 to 5.0% by weight, 0.1 to 5.0% by weight of one or more nonionic surfactants selected from polyoxyethylene alkylphenol ether formalin condensate or polyoxyethylene styrenated phenol ether, and the yield value at 25 ° C. is 10 dyne / It is characterized in that the heteropolysaccharide is sufficiently present so as to have a cm ² or more, and that it can be used as a mixture with other agricultural chemical emulsions.

Examples of pesticides that can be used in the present invention include 2-t-butylimino-3-isopropyl-5-phenyl-3,4,5,6-tetrahydro-2H-1,3,5-thiadiazin-4-one [general name Buprofezin] and / or 3′-isopropoxy-2-trifluorotoluanilide [generic name flutolanil].

These pesticides may be used alone or in combination.

The content ratio of the above-mentioned pesticide is 50% by weight or less, preferably 10 to
50% by weight.

As the polyoxyethylene alkylphenol ether used in the present invention, polyoxyethylene nonylphenol ether and the like can be used, and the compounding ratio thereof is 0.1 to 5.0% by weight, preferably 0.1 to 3% by weight.

As the nonionic surfactant, one or more kinds selected from polyoxyethylene alkylphenol ether formalin condensate or polyoxyethylene styrenated phenol ether may be blended. These surfactants may be used alone or in combination.

The blending ratio of the nonionic surfactant can be appropriately selected from the range of 0.1 to 5.0% by weight.

Heteropolysaccharides are used as water-soluble thickeners and are generally used as xanthan gum.
It is a high molecular weight linear extracellular substance produced by the bacterial action of the genus Xanthomonas. It has a molecular weight of more than 200,000, preferably 1,000,000 or more. The heteropolysaccharide may be blended in an amount sufficient to yield a yield value at 25 ° C. of the agricultural chemical preparation in suspension of 10 dyne / cm ² or more, preferably 0.05 to 0.5% by weight. When the amount of xanthan gum added is such that the yield value of the pesticide formulation is 10 dyne / cm ² or less, the active ingredient precipitates, redispersion becomes difficult, and physical stability becomes a problem.

The solvent used in the waterborne pesticide formulation of the present invention,
Mainly water, may be water alone, if necessary, a hydrophilic solvent such as methyl alcohol, ethyl alcohol, isopropyl alcohol, polyethylene glycol, ethylene glycol, propylene glycol, or in some cases xylene, toluene, kerosene, mineral oil, vegetable oil, One or more organic solvents selected from hydrophobic solvents such as liquid paraffin may be blended. When blending an organic solvent 1 to
30% by weight, preferably 10 to 20% by weight.

In the present invention, in addition to the above components, if necessary, 5% by weight or less of an antifoaming agent, for example, a silicone antifoaming agent containing dimethylpolysiloxane as a main component may be blended. As an auxiliary agent, 5% by weight or less of hydrophilic silica or the like may be blended if necessary, and further, other components may be blended if necessary. Other pesticides that can be used as a mixture with the pesticide suspension in water of the present invention include MEP emulsion, BPMC emulsion, MEP emulsion.
-BPMC emulsion, diazinon emulsion, PAP emulsion, isoprothiolane emulsion, marathon emulsion, IBP emulsion and the like can be mentioned, but the present invention is not limited thereto.

As an example of the production process of the present invention, for example, polyoxyethylene alkylphenol ether, a nonionic surfactant and optionally a defoaming agent, a predetermined amount of an organic solvent is suspended or dissolved in water by a stirrer, The active ingredients are then added and the mixture is wet milled to give
Finely pulverized to a size of less than or equal to μm, preferably 0.5 to 3.0 μm, and then adding a predetermined amount of heteropolysaccharide,
Mix evenly to obtain the product.

Next, examples and test examples of the present invention will be shown. In addition, "parts in each example" means "parts by weight".

Example 1 Buprofezin 42.00 parts Polyoxyethylene (10 mol) Nonylphenol ether 1.40 parts Polyoxyethylene (24 mol) Styrenated phenol ether 2.00 parts Propylene glycol 3.00 parts Defoamer 0.50 parts Heteropolysaccharide 0.15 parts Hydrophilic silica 3.00 parts Water 47.95 Parts Polyoxyethylene (10 mol) nonylphenol ether 1.40 parts, polyoxyethylene (24 mol) in 47.95 parts of water
Add 2.00 parts of styrenated phenol ether, 3.00 parts of propylene glycol and 0.50 parts of antifoaming agent (Silicone KM-73, manufactured by Shin-Etsu Chemical Co., Ltd.) and add a regular stirrer (Homomixer HV-M type, Tokushu Kika Kogyo Co., Ltd.). 20) for 20 minutes, and then 42.0 parts of buprofezin and hydrophilic silica (Carplex ^{# 80} , Shionogi Pharmaceutical Co., Ltd.) are added, and the mixture is mixed with a wet pulverizer (attritor; Mitsui Miike Seisakusho Co., Ltd.) Milled for hours. Add 0.15 parts of heteropolysaccharide and mix for 20 minutes to obtain a uniform preparation 100
I got a part.

Similarly, the formulations of Examples 2 to 9, Reference Examples 1 to 10, Examples 10 to 12 and Reference Examples 11 to 15 were prepared. The prescriptions are shown in Table 1, Table 2 and Table 3.

Test Example 1 The viscosity (apparent viscosity and yield value) and physical standing stability (sedimentation volume ratio) of the preparations obtained in Examples and Reference Examples were measured by the following methods.

Viscosity: Using an E-type viscometer (manufactured by Tokyo Keiki Seisakusho Co., Ltd.), keep the product temperature at 25 ° C and measure.

The corn used is 1 34 minutes corn.

The apparent viscosity is the viscosity at a shear rate of 100 sec ^-1 .

Yield value Shear stress at shear rate 0 sec ^-1 is shown.

Sedimentation volume ratio: 20 ml of the preparation of the present invention or the preparation of the comparative example is put into a measuring cylinder with an internal diameter of 1.3 cm and a capacity of 20 ml, and the mixture is left to stand in a thermostat at 40 ° C for 1 month. Volume of suspended layer after standing Vml
Is measured, and the ratio of this suspension layer to the total volume is determined as the sedimentation volume ratio by the following formula.

This value is used as an index of physical static stability.

The results are shown in Table 4.

Test Example 2 Mixing test Water is put in a 500 ml wide-mouthed bottle, and then a predetermined amount of a commercially available emulsion is put therein, and well stirred to uniformly emulsify and disperse. Next, a predetermined amount of the preparation of the present invention is added and uniformly dispersed to prepare a mixed drug solution having a dilution concentration corresponding to LV spraying (8 per hectare). After allowing this chemical solution to stand for 2 hours, it was passed through a strainer of 250 mesh, and the possibility of mixing and using was investigated from the amount and properties of the residue on the strainer.

○: No residue, mixed use possible ×: Creamy residue, no mixed use results are shown in Table 5.

Claims (1)

[Claims] 1. 2-t-Butylimino-3-isopropyl-5-phenyl-3,4,5,6-tetrahydro-2H-1,3,5
-Thiadiazin-4-one and / or 3'-isopropoxy-2-trifluorotoluanilide 10 to 50% by weight, polyoxyethylene alkylphenol ether
0.1 to 5.0% by weight, 0.1 to 5.0% by weight of one or more nonionic surfactants selected from polyoxyethylene alkylphenol ether formalin condensate or polyoxyethylene styrenated phenol ether, and the yield value at 25 ° C is 10 dyne / cm. A stable pesticide formulation in water, characterized in that the heteropolysaccharide is sufficiently present so as to be ² or more, and can be mixed with other pesticide emulsions.