JP2020193224A - Aqueous suspension - Google Patents

Abstract

To provide a stable aqueous suspension containing an agrochemical active compound.SOLUTION: An aqueous suspension contains an agrochemical active compound with a water solubility at 25°C of 100000 ppm or less and with a melting point of 35°C or higher, a surfactant, a thickener, a preservative, an antifreezing agent and water.SELECTED DRAWING: None

Description

The present invention relates to an aqueous suspension containing a pesticide active compound.

Conventionally, as one of the forms of agrochemical preparation, an aqueous suspension concentrate called SC in which particles of a solid pesticide active ingredient are suspended in water is known. If the SC precipitates during storage, there is a problem that the user must suspend the SC again when using the SC, and it is desirable that the SC does not easily precipitate.

Certain compounds for controlling pests, plant diseases, etc. are known (for example, Non-Patent Document 1).

The Pesticide Manual, 18th Edition, published by BCPC

An object of the present invention is to provide a stable aqueous suspension which is an aqueous suspension containing a pesticide active compound described later.

The present inventor is an aqueous suspension containing a pesticide active compound, a surfactant, a thickener, a preservative, an antifreeze agent and water having a water solubility at a temperature of 25 ° C. of 100,000 ppm or less and a melting point of 35 ° C. or higher. It was found that the turbid liquid is less likely to settle during storage and separation is suppressed.

The present invention is as follows.
[1] An aqueous suspension containing a pesticide active compound, a surfactant, a thickener, a preservative, an antifreeze agent and water having a water solubility at a temperature of 25 ° C. of 100,000 ppm or less and a melting point of 35 ° C. or higher. ..

According to the present invention, it is possible to provide an aqueous suspension that is less likely to precipitate during storage and whose separation is suppressed.

The aqueous suspension of the present invention (hereinafter, may be referred to as “suspension of the present invention”) is a pesticide active compound (hereinafter, referred to as “suspension of the present invention”) having a water solubility at a temperature of 25 ° C. of 100,000 ppm or less and a melting point of 35 ° C. or higher. , "This compound").

The suspension of the present invention is less likely to precipitate during storage and can suppress separation. In addition, the suspension of the present invention has good dischargeability from the container.

The water solubility of this compound at a temperature of 25 ° C. is usually 100,000 ppm or less, preferably 1000 ppm or less. The melting point of this compound is usually 35 ° C. or higher, preferably 50 ° C. or higher.

Examples of this compound include clothianidin, spinetram, esfenvalerate, fenpropatrin, cypermethrin, etoxazole, diniconazole M, oxolinic acid, diclosimet, flamethopyl, ferlimzone, fusalide, isothianyl, benomil, dietofencarb, procymidone, torquelophosmethyl and fempira. , Mandestrobin, compounds represented by the following formulas (1) to (5) (hereinafter, each of them is "Compound (1)", "Compound (2)", "Compound (3)", "Compound (4)". , And "Compound (5)"), all of which are known compounds.

Compound (1) is described in, for example, International Publication No. 2014/188863, and can be produced by the method described therein.

Compound (2) is described in, for example, International Publication No. 2011/162397, and can be produced by the method described therein.

The compound (2) includes an R-form and an S-form based on the asymmetric carbon atom present in the compound (2).
The positions of the asymmetric carbon atoms in compound (2) are indicated by "*" below.

The content ratio of R-form and S-form (R-form / S-form) contained in compound (2) is not particularly limited, and compound (2) having any content ratio can be used. The content ratio of R-form / S-form is preferably 80/20 or more, and may be 90/10 or more, 95/5 or more, or 98/2 or more.

Compound (3) is described in, for example, International Publication No. 2013/162072, and can be produced by the method described therein.

Compound (4) is, for example, the benzoxazole compound 1-10 described in International Publication No. 2014/10407, and can be produced by the method described therein.

Compound (5) is described in, for example, International Publication No. 2017/065228, and can be produced by the method described therein.

The suspension of the present invention contains at least one compound of the present invention, and the total amount of the compound is usually 1 to 60% by weight, preferably 3 to 50% by weight.

The compound contained in the suspension of the present invention is preferably in a solid state. In other words, the suspension of the present invention preferably contains the compound in a solid state, a surfactant, a thickener, a preservative, an antifreeze agent and water.

The suspension of the present invention contains at least one surfactant. Examples of the surfactant include anionic surfactants, nonionic surfactants, cationic surfactants, amphoteric surfactants and mixtures thereof.
Preferred surfactants are anionic and / or nonionic surfactants. Preferred anionic surfactants are sulfonates, sulfates, phosphates, carboxylates and mixtures thereof. Examples of the sulfonate include naphthalene sulfonate and its formaldehyde condensate, alkylbenzene sulfonate, alkylnaphthalene sulfonate, alkyldiphenyl ether disulfonate, α-olefin sulfonate, lignin sulfonate, and polyoxyethylene. Included are alkylphenyl ether sulfonates and dialkyl sulfosulfates. Examples of the sulfate ester salt include an alkyl sulfate ester salt, a polyoxyethylene alkyl ether sulfate ester salt, and a polyoxyethylene alkyl phenyl ether sulfate ester salt. Examples of the phosphoric acid ester salt include polyoxyethylene alkylaryl ether phosphoric acid ester salt and polyoxyethylene tristyrylphenyl ether phosphoric acid ester salt. Carboxylates include, for example, fatty acid salts and polycarboxylic acid salts. Examples of the nonionic surfactant include polyoxyethylene alkyl ether, polyoxypropylene alkyl ether, polyoxyethylene polyoxypropylene alkyl ether, polyoxyethylene distyrylphenyl ether, polyoxyethylene tristyrylphenyl ether, and sucrose fatty acid. Esters, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, glycerin fatty acid esters, polyoxyethylene fatty acid esters, polyoxyethylene alkylamines, alkylalkanolamides, polyoxyethylene polyoxypropylene block copolymers, alkylpolygcosides and Acrylic copolymers can be mentioned.
Examples of the cationic surfactant include alkylamine salts and quaternary ammonium salts.
Examples of the amphoteric surfactant include alkyl betaine.

The suspension of the present invention generally contains 0.5 to 30% by weight, preferably 1 to 20% by weight or 1 to 15% by weight of the surfactant in total.

The suspension of the present invention contains at least one thickener. Preferred thickeners are polysaccharides such as xanthan gum, clays, and silicates.
The suspension of the present invention generally contains 0.05 to 5% by weight, preferably 0.07 to 3% by weight of the thickener in total.

The suspension of the present invention contains at least one preservative. Preferred preservatives are isothiazolinone-based preservatives.
The suspension of the present invention generally contains 0.05 to 0.5% by weight, preferably 0.1 to 0.3% by weight of preservatives in total.

The suspension of the present invention contains at least one antifreeze agent. Preferred antifreeze agents are ethylene glycol, propylene glycol, urea and glycerin.
The suspension of the present invention generally contains 1 to 10% by weight, preferably 2 to 8% by weight, of the antifreeze agent in total.

The suspension of the present invention contains water. Examples of water include ion-exchanged water, tap water and groundwater.
The suspension of the present invention usually contains 30 to 98% by weight, preferably 40 to 90% by weight of water.

The suspension of the present invention may contain other formulation aids as needed. Other formulation aids include, for example, antifoaming agents.

A suitable defoaming agent is a silicone-based defoaming agent. When the suspension of the present invention contains a defoaming agent, the content of the defoaming agent in the entire suspension of the present invention is usually 0.01 to 1% by weight, preferably 0.05 to 0.5% by weight. is there.
However, the suspension of the present invention preferably contains the present compound, a surfactant, a thickener, and water in a total amount of 55% by weight or more, 66% by weight or more, or 75% by weight or more. In addition, the suspension of the present invention preferably contains the present compound, a surfactant, and water in a total amount of 50% by weight or more, 60% by weight or more, or 70% by weight or more.

The loss tangent tan δ of the suspension of the present invention is preferably 0.40 or more, more preferably 0.42 or more, still more preferably 0.45 or more. The loss tangent tan δ of the suspension of the present invention is preferably 0.75 or less, more preferably 0.72 or less, still more preferably 0.70 or less.
The loss tangent tan δ of the aqueous suspension is calculated by the following formula (i).
tan δ = G'' / G'(i)
However, in the formula (a), G'represents the storage elastic modulus and G'represents the loss elastic modulus.
In the present specification, the storage elastic modulus and the loss elastic modulus each refer to values measured using a stress-controlled rotary rheometer (hereinafter referred to as a rheometer). For the loss tangent tan δ of the aqueous suspension, use a rheometer to determine the storage elastic modulus and loss elastic modulus using a cone plate with a diameter of 60 mm as a jig under the conditions of strain 2%, angular frequency 10 rad / s, and temperature 20 ° C. It is a value measured and calculated by the above formula (i).

The zeta potential of the suspension of the present invention is preferably −45 mV or less, more preferably −50 mV or less, still more preferably −52 mV or less. The zeta potential of the suspension of the present invention is preferably −85 mV or higher, more preferably −80 mV or higher, and even more preferably −79 mV or higher.
In the present specification, the zeta potential refers to the zeta potential measured by the electrophoretic light scattering method, and the zeta potential of the aqueous suspension is measured using a zeta potential measuring device whose measurement principle is the electrophoretic light scattering method. Will be done. As the zeta potential measuring device, a zeta potential measuring device of Malvern Co., Ltd., a zeta potential measuring device (for example, Zeta Sizer Nano ZSP, Zeta Sizer Nano ZS, Zeta Sizer Nano Z, Zeta Sizer Nano ZS90) is used. Specifically, the zeta potential of the aqueous suspension is obtained by diluting the aqueous suspension with ion-exchanged water 200-fold using any zeta potential measuring device of the Zetasizer Nano series. The cell is filled and measured at a temperature of 25 ° C.

Suspensions of the present invention are prepared by methods known per se in SC preparation, eg, the compounds, surfactants, thickeners, preservatives, antifreezes and water, and optionally additional formulation aids. It can be prepared by mixing the agents.

The particle size of the particles of the present compound in the suspension of the present invention can usually be 0.1 μm or more, preferably 0.5 μm or more or 1 μm or more. The particle size of the particles of the present compound in the suspension of the present invention can be usually 5 μm or less, preferably 4 μm or less or 3 μm or less.

The method for producing the suspension of the present invention is illustrated below.
A1) The compound, surfactant, water, and if necessary, a formulation auxiliary agent are mixed to obtain a suspension.
A2) The obtained suspension is supplied to a crusher such as a bead mill, and the compound in the suspension is pulverized to obtain a suspension (hereinafter, may be referred to as "crushed suspension").
A3) A thickener, a preservative, an antifreeze agent, an auxiliary agent for preparation, etc., if necessary, are added to the obtained pulverized suspension and mixed to obtain the suspension of the present invention.
The crushing time in the step of obtaining the crushed suspension of A2) (in the case of a continuous crusher, the supply speed of the suspension to the crusher), the type of crusher used and its operating conditions (in the case of a bead mill). By appropriately adjusting the temperature of the suspension during pulverization (bead size, etc.), the loss tangent tan δ and the zeta potential of the suspension of the present invention are adjusted. The loss tangent tan δ and the zeta potential are preferably adjusted within the above ranges.
When using a batch type bead mill, the smaller the bead size, the smaller the loss tangent tan δ, the longer the crushing time, the smaller the loss tangent tan δ, and the lower the temperature of the suspension during crushing, the smaller the loss tangent tan δ. tan δ becomes smaller.
The zeta potential of the suspension of the present invention is the interface in the step of adjusting the content of the surfactant in the suspension of the present invention or dividing and adding the surfactant to obtain the suspension of A1) above. It can be adjusted by appropriately adjusting the amount of the activator added.

By applying the suspension of the present invention to a plant or its growing environment, it is possible to control pests, plant diseases and the like in which the pesticide active compound contained in the suspension of the present invention exhibits control activity.

The user usually applies the suspension of the invention from a knapsack sprayer, a spray tank, a spray plane, or an irrigation system. Usually, the suspension of the present invention is diluted with water to the desired application concentration to obtain a spray solution. Usually, 20 to 2000 L, preferably 50 to 400 L of spray liquid per hectare is applied.

The application rate of the suspension of the present invention includes the type and content of the pesticide active compound contained in the suspension of the present invention, the type of plant, the type and frequency of occurrence of pests and plant diseases to be controlled, the application time, and the like. It is adjusted appropriately according to the application method, application location, weather conditions, etc.

Hereinafter, the present invention will be described in more detail with reference to Examples and Test Examples.

[Example 1]
A suspension obtained by mixing the present compound, a surfactant (for example, an anionic surfactant or a nonionic surfactant), a defoaming agent (for example, a silicone-based defoaming agent) and ion-exchanged water is put into a bead mill. The compound is fed and pulverized in the suspension to obtain a pulverized suspension. By adding a thickener (for example, xanthan gum-based thickener, silicate-based thickener), a preservative (for example, isothiazolinone-based preservative) and an antifreeze agent to the pulverized suspension and mixing them. Prepare the suspension of the present invention. The suspension contains 20-40% by weight of the compound, 1-15% by weight of surfactant, 0.1 to 3% by weight of thickener, 0.05 to 0.5% by weight of preservative. It contains 1-10% by weight of antifreeze, 0.05-1% by weight of defoamer, and an amount of ion-exchanged water that makes the entire aqueous suspension 100% by weight.

[Examples 2 to 7]
Using the present compounds shown in Table 1, suspensions 2 to 7, which are suspensions of the present invention, were prepared according to the method described in Example 1, respectively. The content ratio of R-form and S-form in the compounds (2) used in Examples 3 and 4 was 98/2 for R-form / S-form.

[Measurement of loss tangent tan δ of aqueous suspension]
For each of the suspensions 2 to 7, a rheometer AR-G2 (TA Instruments) was used, and a cone plate having a diameter of 60 mm was used as a jig under the conditions of a strain of 2%, an angular frequency of 10 rad / s, and a temperature of 20 ° C. The loss tangent tan δ was calculated by measuring the storage elastic modulus and the loss elastic modulus. The results are shown in Table 2.

[Measurement of zeta potential of aqueous suspension]
For each of the suspensions 2 to 7, a sample obtained by diluting each suspension 200 times with ion-exchanged water using a zeta potential measuring device (Zetasizer Nano ZSP, manufactured by Malvern) was put into a capillary cell. It was filled and the zeta potential was measured under the condition of a temperature of 25 ° C. The results are shown in Table 2.

[Test Example 1]
For each of the suspensions 2 to 7, 10 g of each suspension was placed in a glass vial having a capacity of 10 mL, and the degree of separation after storage at a temperature of 54 ° C. for 2 weeks was measured. The degree of separation was calculated by the following formula (ii), where x was the height [mm] of the entire suspension in the vial and y was the height [mm] of the supernatant generated by the separation. The degree of separation of each suspension was less than 20%, confirming that the separation was suppressed.
Separation [%] = y / x × 100 (ii)

[Test Example 2]
For each of the suspensions 2 to 7, 10 g of each suspension was placed in a glass vial having a capacity of 10 mL, and the discharge property was measured after storage at a temperature of 54 ° C. for 2 weeks. For dischargeability, the lid of the glass vial is removed, the suspension is held for 3 minutes with the mouth facing straight down, the suspension is discharged from the vial, and the suspension weight [g] in the vial before discharge is a. The suspension weight [g] in the vial after discharge was defined as b, and the discharge property was calculated by the following formula (iii). Both suspensions had good discharge properties of less than 10%.
Emission [%] = b / a × 100 (iii)

Claims (1)

An aqueous suspension containing a pesticide active compound, a surfactant, a thickener, a preservative, an antifreeze agent and water having a water solubility at a temperature of 25 ° C. of 100,000 ppm or less and a melting point of 35 ° C. or higher.