CN117770239A - Suspending agent for controlling agricultural pests and preparation method thereof - Google Patents

Abstract

The suspending agent for preventing and controlling agricultural pests and the preparation method thereof solve the problems that dinotefuran is easy to crystallize and paste after being prepared into the suspending agent, the obtained suspending agent has good stability, mainly has good dispersibility and high suspension rate, the suspension rate of active ingredients is above 98 percent, and the heat storage stability and the freeze thawing stability of the product are good, the crystallization and the paste are not separated out in the heat storage test process and at room temperature after the heat storage test is finished, and the crystallization and the paste are not separated out in the freeze thawing test process and at room temperature after the freeze thawing test is finished.

Description

Suspending agent for controlling agricultural pests and preparation method thereof

Technical Field

The invention belongs to the field of pesticide preparations, and particularly relates to a suspending agent for controlling agricultural pests and a preparation method thereof.

Background

Dinotefuran is the only third generation of nicotinic pesticides containing tetrahydrofuran rings at present, and the target of the dinotefuran is an acetylcholine receptor agonist, so that insects die in an extremely excited state by inhibiting the acetylcholine receptor. Dinotefuran not only has the effects of contact killing and stomach poisoning, but also has excellent systemic, osmotic and conductive effects, is mainly used for preventing and controlling aphids, leafhoppers, plant hoppers, thrips, whiteflies and resistant strains thereof on various crops such as wheat, rice, cotton, vegetables, fruit trees, tobacco leaves and the like, and is also efficient on coleopteran, dipteran, lepidoptera and homoptera pests, wherein the dinotefuran (dinotefuran) has the CAS accession number of [165252-70-0], and has the chemical structural formula:

the tolfenpyrad is a novel pyrazole amide insecticidal acaricide, and the action mechanism is that the electron transmission is blocked by blocking an electron transmission system of an insect mitochondrial energy metabolism system, so that the oxidative phosphorylation of insects is prevented, and the insects cannot supply and store energy to die. Tolfenpyrad is known to have high efficiency, broad spectrum, low toxicity and quick acting, has the functions of killing eggs, inhibiting food, inhibiting spawning and sterilizing, can well play a role of contact killing, has extremely strong control effect on various lepidoptera, hemiptera, beetle, hymenoptera and diptera pests and mites, and is widely used for pest control on crops such as vegetables, fruit trees, flowers, tea leaves and the like. The effect of the agent is quick, and once the agent is sprayed, pests die; has better control effect on fungal diseases.

Tolfenpyrad (tolfenpyrad), CAS registry number [129558-76-5], chemical structural formula:

the dinotefuran and the tolfenpyrad have different action mechanisms, and the reasonable combination of the dinotefuran and tolfenpyrad can enlarge the insecticidal spectrum, improve the control effect and delay the occurrence of pest drug resistance. The solubility of dinotefuran in water is 39.8g/L (20 ℃), and the melting point is 107.5 ℃; the solubility of tolfenpyrad in water is 0.087mg/L (25 ℃), and the melting point is 87.8 ℃. From the physical and chemical properties of the dinotefuran, the dinotefuran has high water solubility, while tolfenpyrad has a relatively low melting point. According to the requirements of the suspending agent on the physicochemical properties of the active ingredients, the solubility of the active ingredients in water is preferably lower than 100mg/L, and the melting point is preferably higher than 100 ℃, so that the technical difficulty of preparing the suspending agent by using the active ingredients with high solubility or low melting point in water is higher, and the quality risk is higher.

Experiments show that the dinotefuran and tolfenpyrad-containing suspending agent has the biggest difficulty in preparing the dinotefuran-containing suspending agent that the dinotefuran-containing suspending agent has too high solubility in water, and the product is easy to have the problems of room temperature crystallization and creaming bottom after the heat storage test is ended, the room temperature crystallization and creaming bottom after the freeze thawing test is ended, and the product cannot be used or the using effect is influenced. The technical problem is also the common difficulty problem encountered in the development of dinotefuran-containing and compound suspending agent products in the current industry.

Chinese patent CN104397007a discloses a high-efficiency pesticide composition for killing agricultural pests, the main component of which is flubendiamide, biopesticide Lepimectin, dinotefuran and tolfenpyrad, and the related formulation includes emulsifiable concentrate, suspending agent, wettable powder, water dispersible granule, aqueous emulsion or microemulsion, but the invention content does not describe in detail how to obtain stable suspending agent.

Chinese patent CN104286005A discloses a high-efficiency pesticide containing fenpropathrin, biological pesticide Lepimectin, dinotefuran and tolfenpyrad, and the related dosage forms comprise emulsifiable concentrate, suspending agent, wettable powder, water dispersible granule, aqueous emulsion or microemulsion, and the invention content of the pesticide does not make detailed explanation on how to obtain a stable suspending agent.

Chinese patent CN104920440a discloses a low-volume spray containing tolfenpyrad and dinotefuran, which comprises the following raw materials: 10-50% of tolfenpyrad, 1-20% of dinotefuran, 5-15% of tea saponin and the balance of water. From the raw material formulation, the invention is not practical by just wetting agent tea saponin to maintain system stability, and there is no specific data in this patent for the stability of the obtained spray.

Chinese patent CN103960277a discloses a pesticide composition containing tolfenpyrad and dinotefuran, wherein the formulation involved is a suspending agent, and the formulation components thereof are summarized, but the stability thereof is not evaluated in a related manner, and no specific examples are provided.

At present, aiming at the problem that the suspending agent prepared by the dinotefuran and the tolfenpyrad is easy to have crystallization and paste formation, how to improve the stability of the product is a difficulty of the current research.

Disclosure of Invention

The invention aims to provide a suspending agent for preventing and controlling agricultural pests and a preparation method thereof, solves the problems that dinotefuran is easy to crystallize and paste after being prepared into a suspending agent, lays a solid foundation for industrial production of dinotefuran-tolfenpyrad suspending agent products, and provides a brand-new solution thinking for solving the technical problems of crystallization and paste of suspending agents containing dinotefuran and compound pesticides thereof.

In order to achieve the above purpose, the present invention provides the following technical solutions:

a suspending agent for controlling agricultural pests comprises dinotefuran, a salifying agent, a wetting dispersant, an antifreezing agent, a thickening agent, a preservative, a defoaming agent, a stabilizer and water.

The pesticide suspending agent for controlling agricultural pests also comprises tolfenpyrad, and the weight percentages of the components are as follows: 1 to 20 percent of dinotefuran, 1 to 40 percent of tolfenpyrad, 0.01 to 6 percent of salifying agent, 3 to 12 percent of wetting dispersant, 3 to 15 percent of antifreezing agent, 0.1 to 3 percent of thickening agent, 0.1 to 1 percent of preservative, 0.1 to 1 percent of defoaming agent, 0 to 2 percent of stabilizer, and the balance of water, wherein the pH value is 5.0 to 8.0;

the salifying agent is any one of sodium hydroxide and potassium hydroxide;

the wetting dispersant is one or more of a macromolecular amphiphilic surfactant, polycarboxylate and lignosulfonate.

Preferably, the antifreezing agent is one or more of ethylene glycol, propylene glycol, glycerol and inorganic salts.

Preferably, the thickener is one or two of magnesium aluminum silicate or xanthan gum.

Preferably, the preservative is one or more of sodium benzoate, 1, 2-benzisothiazolin-3-one and Kathon.

Preferably, the defoaming agent is an organosilicon defoaming agent.

Preferably, the stabilizer is hydrochloric acid, sulfuric acid, oxalic acid, benzoic acid, citric acid or glacial acetic acid.

Preferably, the sum of the weight percentages of the dinotefuran and the tolfenpyrad is 1-50%, and preferably, the weight ratio of the emamectin benzoate to the cyantraniliprole is 10:1-1:20.

Preferably, the wetting dispersant is a mixture of a macromolecular amphiphilic surfactant, a polycarboxylate and lignin sulfonic acid, preferably, the macromolecular amphiphilic surfactant is SP-SC29, the polycarboxylate is SP-27001, and the lignin sulfonate is SP-SC3220F; wherein, SP-SC29: SP-27001: SP-SC3220F mass ratio= (1-3): (1-6): (1-3).

In order to ensure that the suspending agent containing dinotefuran for controlling agricultural pests has good stability, good heat storage stability and good freeze-thawing stability, the suspending agent is not crystallized and not creamed at room temperature in the heat storage test process and after the heat storage test is finished, and is not crystallized and not creamed at room temperature in the freeze-thawing test process and after the freeze-thawing test is finished, and the suspending agent is mainly beneficial to:

(1) When the salt adding agent is added, the solubility of dinotefuran in water is very high, the solubility reaches 39.8g/L (20 ℃), the particle size is large due to the fact that the dinotefuran is extremely easy to Oryze in preparation of the suspending agent, the active ingredient particles start to coalesce and aggregate along with the continuous increase of the particle size, and finally the active ingredient particles are crystallized or creamed and bottom and the like. The invention breaks through the traditional preparation thought of the conventional suspending agent, and part of dinotefuran technical stock reacts with the salifying agent to form salt so as to increase the solubility of the dinotefuran technical stock in water, ensure that the dinotefuran components are all dissolved in water under different environmental conditions, and effectively avoid the growth and crystallization of particle size of the dinotefuran technical stock caused by large solubility in water. Therefore, in the pesticide suspending agent containing the dinotefuran and the tolfenpyrad, the physical form of the pesticide suspending agent is that the dinotefuran is completely dissolved in water instead of being suspended in the water in a particle form, and the tolfenpyrad is suspended in the water in a particle form, so that the pesticide suspending agent has a good insect prevention effect under the condition of ensuring the stability of the suspending agent.

(2) Based on the invention, the salt forming agent is selectively added to keep the stability of the suspending agent, and further, the wetting dispersant selected to be used in the invention is a mixture of a macromolecular amphiphilic surfactant, polycarboxylate and lignin sulfonic acid, preferably, the macromolecular amphiphilic surfactant is SP-SC29, the polycarboxylate is SP-27001, and the lignin sulfonate is SP-SC3220F; and controls, SP-SC29: SP-27001: SP-SC3220F mass ratio= (1-3): (1-6): (1-3).

The main reason is that the macromolecular amphiphilic surfactant SP-SC29 has a structure similar to a Gemini structure, and increases the thickness of an electric double layer on the surface of particles under the action of external forces such as a colloid mill or high-speed shearing force. The polycarboxylate dispersant SP-27001 has the main function of providing larger electrostatic repulsive force and steric hindrance, so as to reduce agglomeration among the raw material particles. The lignosulfonate SP-SC3220F is mainly lignosulfonate with high sulfonation degree and low molecular weight, has remarkable effect on controlling the growth of crystal particle size, firstly contains a large number of sulfonate groups, can effectively improve the ionic strength in a formula, enhances the salt resistance of a system, forms a salt-containing suspending agent system because dinotefuran reacts with a salifying agent to form salt, and is mostly non-salt-tolerant to wetting dispersant, the suspension dispersing function of the dispersant can be reduced under the salt-containing system, so that the active ingredient particles are easy to agglomerate and grow up, and secondly can be effectively attached to the surfaces of some bare active ingredient particles, so that the agglomeration between active ingredient molecules and particles is reduced, and the effects of reducing and slowing down the crystal crystallization and the growth of the particle size are achieved; thirdly, the lignosulfonate has aromatic flavor, so that the product also has aromatic flavor.

The invention adopts the SP-SC29, SP-27001 and SP-SC3220F to play a role of cooperative suspension and dispersion, effectively controls the growth of the particle size of the raw materials in the salt-containing suspending agent system, and improves the stability of the product.

The suspending agent product obtained by the invention is added with a freeze-thawing stability test evaluation means, and the specific operation method comprises the following steps: the test sample is stored for 24 hours at low temperature (-18 ℃), the temperature is changed to room temperature, the temperature is changed to high temperature (54 ℃) for 24 hours, and the process is circulated three times. Because the environmental temperature conditions are continuously changed, and the solubility of the active ingredients in water is changed along with the temperature change, the stability of the product can be evaluated from different dimensions by increasing a freeze thawing stability test for preparing the suspending agent from the active ingredients with high water solubility, thereby ensuring the quality stability of the formula under different environmental conditions.

The suspending agent for preventing and controlling agricultural pests, which is obtained by the invention, has good stability, high suspension rate and high heat storage stability and freeze thawing stability, and the suspending agent mainly has good dispersibility, high suspension rate, and the suspension rate of active ingredients is more than 98 percent.

The invention relates to a preparation method of a suspending agent for controlling agricultural pests, which specifically comprises the following steps:

1) According to the design of the components, mixing a thickener, a preservative and water to prepare a thickener aqueous solution with the concentration of 1-2 wt%, shearing for 30-40 min, standing for more than 24h to obtain a cured thickener aqueous solution for standby;

2) Uniformly mixing a wetting dispersant, an antifreezing agent, a defoaming agent and water to obtain a material 1, wherein the adding amount of the defoaming agent is 30-70% of the total amount of the defoaming agent, and the adding amount of the water is 30-60% of the total amount of the water;

3) Adding a cured thickener aqueous solution, dinotefuran and/or tolfenpyrad raw material into the obtained material 1, shearing 25-30 mm until the materials are uniformly mixed to obtain a material 2, wherein the temperature of the material in the shearing process is not more than 30 ℃; wherein, the addition amount of the cured thickener aqueous solution is 0-40% of the total amount of the thickener aqueous solution; the addition amount of dinotefuran is 0-2% of the total amount;

4) The obtained material 2 is sanded, the grain diameter D90 is controlled to be 2-4 mu m after the sanding, and the material 3 is obtained for standby after the sanding is finished; the sanding temperature is not more than 25 ℃;

5) Mixing the rest dinotefuran, the salifying agent and water, stirring for 1.5-2 h at 1440r/min until the materials are mixed uniformly and react completely to obtain a material 4 for later use; wherein the addition amount of water is 40-70% of the total amount of water, and the mol ratio of the salifying agent to dinotefuran is 1:1; then adding the material 3 into the material 4, shearing for 25-30 min until the materials 5 are obtained after uniform mixing, wherein the grain diameter D90 of the sheared materials 5 is less than or equal to 5 mu m, and the temperature of the materials in the shearing process is not more than 30 ℃;

6) Adding the stabilizer, the residual cured thickener aqueous solution, the residual defoamer and the residual water into the material 5, stirring for 20-25 min until the materials are uniformly mixed, and obtaining the pesticide suspending agent for controlling agricultural pests.

In the invention, in the step 3), 0 to 2 percent of dinotefuran is added first, and the dinotefuran does not react with the salifying agent, so that the method has the advantages of ensuring that the salt after the dinotefuran reacts with the salifying agent is completely dissolved in water, and controlling the pH value of a product system between 5.0 and 8.0, thereby ensuring the chemical stability of the suspending agent. Experiments show that if dinotefuran is salified completely, the pH value of a product system is very high and even exceeds 12.0, and the pH value cannot be adjusted to be between 5.0 and 8.0 by adding a stabilizer, so that the chemical stability of the product is difficult to ensure.

In the subsequent reaction process of the residual dinotefuran and the salifying agent, the molar ratio of the salifying agent to the dinotefuran is controlled to be 1:1, and the consumption of the salifying agent is determined by the content of the dinotefuran.

The application of the suspending agent for controlling agricultural pests is characterized by being used for controlling tea leafhoppers of tea trees.

The suspending agent for controlling agricultural pests provided by the invention generally adopts an application method of stem and leaf spraying, and can also adopt other application technologies applied to agriculture according to the needs.

Compared with the prior art, the invention has the following beneficial effects:

(1) The invention provides a brand new experimental thought, part of dinotefuran reacts with a salifying agent to form salt, so that the dinotefuran exists in water in a dissolved form in the whole suspending agent system, the problem that the dinotefuran grows up in particle size and is crystallized due to high solubility in water is effectively avoided, and a brand new solving thought is provided for solving the technical problems of suspending agent crystallization and creaming and end formation of the suspending agent containing the dinotefuran and the compound pesticide thereof, which is not involved in the conventional suspending agent formula development.

(2) The suspending agent containing dinotefuran and tolfenpyrad is prepared by selecting a proper auxiliary agent system, the suspending agent containing dinotefuran and tolfenpyrad has good dispersibility, high suspension rate and high heat storage stability and freeze thawing stability of the product, and the problems of crystallization and creaming and bottom formation in the heat storage test process and the freeze thawing test process and the room temperature are solved.

(3) In the preparation process, dinotefuran is added twice, so that 0-2% of dinotefuran in the suspending agent is ensured not to react with the salifying agent, the pH value of a suspending agent system is controlled between 5.0 and 8.0, the chemical stability of the suspending agent is ensured, and the whole process is simple and convenient and easy to industrialize. The obtained suspending agent has good use effect on preventing tea leafhoppers of tea trees.

Detailed Description

To facilitate understanding of the present invention, examples are set forth below. It will be apparent to those skilled in the art that the examples are merely to aid in understanding the invention and are not to be construed as a specific limitation thereof. In these examples, all percentages are by weight unless otherwise indicated. The various materials described in this invention are commercially available from public sources.

The contents of the components of the suspending agents for controlling agricultural pests in examples 1 to 6 of the present invention are shown in tables 1 and 2, and the specific preparation steps are as follows:

1) According to the design of the components, mixing a thickener, a preservative and water to prepare a thickener aqueous solution with the concentration of 1-2 wt%, shearing for 30-40 min, standing for more than 24h to obtain a cured thickener aqueous solution for standby;

2) Uniformly mixing a wetting dispersant, an antifreezing agent, a defoaming agent and water to obtain a material 1, wherein the adding amount of the defoaming agent is 30-70% of the total amount of the defoaming agent, and the adding amount of the water is 30-60% of the total amount of the water;

3) Adding a cured thickener aqueous solution, dinotefuran and/or tolfenpyrad raw material into the obtained material 1, shearing 25-30 mm until the materials are uniformly mixed to obtain a material 2, wherein the temperature of the material in the shearing process is not more than 30 ℃; wherein, the addition amount of the cured thickener aqueous solution is 0-40% of the total amount of the thickener aqueous solution; the addition amount of dinotefuran is 0-2% of the total amount;

4) The obtained material 2 is sanded, the grain diameter D90 is controlled to be 2-4 mu m after the sanding, and the material 3 is obtained for standby after the sanding is finished; the sanding temperature is not more than 25 ℃;

5) Mixing the rest dinotefuran, the salifying agent and water, stirring for 1.5-2 h at 1440r/min until the materials are mixed uniformly and react completely to obtain a material 4 for later use; wherein the addition amount of water is 40-70% of the total amount of water, and the mol ratio of the salifying agent to dinotefuran is 1:1; then adding the material 3 into the material 4, shearing for 25-30 min until the materials 5 are obtained after uniform mixing, wherein the grain diameter D90 of the sheared materials 5 is less than or equal to 5 mu m, and the temperature of the materials in the shearing process is not more than 30 ℃;

6) Adding the stabilizer, the residual cured thickener aqueous solution, the residual defoamer and the residual water into the material 5, stirring for 20-25 min until the materials are uniformly mixed, and obtaining the pesticide suspending agent for controlling agricultural pests.

The obtained suspending agent for controlling agricultural pests was tested for its suspension rate, pourability, wet sieve test, long-lasting foamability, low-temperature stability, heat storage stability and the like, and the test data are shown in table 3.

The suspension rate measuring method comprises the following steps: see GB/T14825-2006.

The pH value measuring method comprises the following steps: see GB/T1601-1993.

Fineness determination method (i.e., wet sieve test): see GB/T16150-1995.

Pourability test assay method: see GB/T31737-2015.

Method for measuring permanent foamability: refer to GB/T28137-2011.

Method for measuring heat storage stability: see GB/T19136-2021.

The method for measuring the low-temperature stability comprises the following steps: see GB/T19137-2003.

As can be seen from Table 3, the suspending agent products for controlling agricultural pests prepared in examples 1 to 6 are excellent in suspension rate, pourability, wet screening test, long-lasting foamability, cold storage stability (0 ℃,7 d), freeze thawing stability (three cycles), heat storage stability (54 ℃,14 d) and the like, wherein the products are good in heat storage and freeze thawing stability, the water separation rate is lower than 5%, the particle size growth is not obvious, crystallization is not caused, the bottom is not caused, the fluidity is good, and the heat storage degradation rates of dinotefuran and tolfenpyrad are lower than 5%.

1. Experiment for preventing and controlling tea leafhopper of tea tree

The tea tree is 80-120 cm high, the coverage is more than 95%, the growth vigor is good, the control object is tea lesser leafhopper nymphs, and the tea tree is in the initial stage of growing. The backpack type manual sprayer is adopted to prepare the liquid medicine according to the test design concentration, the tea leaves are uniformly sprayed with the liquid medicine on the canopy, the tender tips and the adult leaves of the tea tree endangered by the tea leafhoppers are sprayed with the liquid medicine, and the liquid medicine amount of the treatment area is converted into 75 kg of liquid medicine amount per 667.67 square meters. The test cells are arranged randomly, and each cell has an area of 100 square meters. Each treatment was repeated 4 times and a blank was set.

The drug effect investigation method comprises the following steps: referring to test standard GB/T17980.56-2004, the number of the insect population of the tea leafhopper is investigated before administration, the number of residual live insects is investigated respectively 1d, 3d, 7d, 10d and 15d after administration, and the rate of reduction of the insect population and the correction control effect are calculated. During investigation, 100 tender leaves are randomly investigated in each district, the number of nymphs of the tea leafhoppers on the leaves is investigated, and the number of the live tea leafhoppers is recorded. And meanwhile, the safety of the tea tree in the test process, the influence on other organisms and accidents in the test process are observed and recorded.

The reduction rate of insect population (%) = (number of live insects before drug-number of live insects after drug)/number of live insects before drug x 100%.

Correction control effect (%) = [1- (number of live insects before treatment area of pre-treatment area of post-treatment area of live insects)/(number of live insects after treatment area of control area of pre-treatment area of live insects) ] ×100%.

The 15% dinotefuran/tolfenpyrad suspending agent prepared in example 1 is used for preventing and controlling tea leafhoppers, the dosage of the active ingredients is 75-115 g/hectare, the average prevention effect after 1d is 83.27-92.65%, the average prevention effect after 3d is 87.11-95.86%, the average prevention effect after 7d is 90.64-100%, the average prevention effect after 10d is 89.45-100%, and the average prevention effect after 15d is 84.21-93.87%.

The 20% dinotefuran/tolfenpyrad suspending agent prepared in example 2 is used for preventing and controlling tea leafhoppers, the dosage of the active ingredients is 75-115 g/hectare, the average prevention effect after 1d is 81.83-90.18%, the average prevention effect after 3d is 84.48-92.71%, the average prevention effect after 7d is 88.94-99.36%, the average prevention effect after 10d is 87.26-100%, and the average prevention effect after 15d is 83.74-91.45%.

The 24% dinotefuran/tolfenpyrad suspending agent prepared in example 3 is used for preventing and controlling tea leafhoppers, the dosage of the active ingredients is 75-115 g/hectare, the average prevention effect after 1d is 84.66-93.22%, the average prevention effect after 3d is 88.69-96.75%, the average prevention effect after 7d is 92.13-100%, the average prevention effect after 10d is 91.06-100%, and the average prevention effect after 15d is 84.74-94.52%.

The 25% dinotefuran/tolfenpyrad suspending agent prepared in example 4 is used for preventing and controlling tea leafhoppers, the dosage of the active ingredients is 75-115 g/hectare, the average prevention effect after 1d is 85.37-93.88%, the average prevention effect after 3d is 89.78-97.46%, the average prevention effect after 7d is 93.94-100%, the average prevention effect after 10d is 92.70-100%, and the average prevention effect after 15d is 85.62-95.16%.

The 32% dinotefuran/tolfenpyrad suspending agent prepared in example 5 is used for preventing and controlling tea leafhoppers, the dosage of the active ingredients is 75-115 g/hectare, the average prevention effect after 1d is 85.08-93.46%, the average prevention effect after 3d is 89.21-97.03%, the average prevention effect after 7d is 93.57-100%, the average prevention effect after 10d is 90.38-97.65%, and the average prevention effect after 15d is 84.12-92.80%.

The 40% dinotefuran/tolfenpyrad suspending agent prepared in example 6 is used for preventing and controlling tea leafhoppers, the dosage of the active ingredients is 75-115 g/hectare, the average prevention effect after 1d is 86.25-94.02%, the average prevention effect after 3d is 90.44-97.82%, the average prevention effect after 7d is 94.57-100%, the average prevention effect after 10d is 91.46-97.94%, and the average prevention effect after 15d is 83.25-91.79%.

The dinotefuran and tolfenpyrad-containing suspending agent product prepared by the invention has excellent effect of preventing and controlling tea leafhoppers of tea trees, and has good quick-acting property and lasting effect. No phytotoxicity symptoms appear during the test period, and the tea tree safety.

The above examples are presented only to aid in understanding the method of the present invention and its core ideas and are not therefore to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several improvements and modifications can be made to the present invention without departing from the spirit and principle of the invention, and these improvements and modifications will fall within the scope of the claims of the invention.

2. Stability comparison experiment

Comparative example 1 differs from inventive example 3 in that the salt former sodium hydroxide was removed.

Comparative example 2 differs from inventive example 4 in that the salifying agent potassium hydroxide was removed.

The suspensions obtained in comparative examples 1 and 2 were subjected to stability tests, respectively, and the specific results are shown in table 4.

As can be seen from the results in Table 4, the suspending agent for controlling agricultural pests prepared by the invention has lower water precipitation rate, no crystallization, no creaming and bottom formation and good heat storage stability and freeze thawing stability. And the dinotefuran and salifying agent-containing suspending agent obtained in the comparative example has obvious crystallization and severe creaming and bottom formation in the heat storage and freeze thawing experiments.

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Claims (10)

1. A suspending agent for controlling agricultural pests, which is characterized by comprising dinotefuran, a salifying agent, a wetting dispersant, an antifreezing agent, a thickening agent, a preservative, an antifoaming agent, a stabilizer and water.

2. The suspending agent for controlling agricultural pests according to claim 1, further comprising tolfenpyrad, and the weight percentages of the components are: 1 to 20 percent of dinotefuran, 1 to 40 percent of tolfenpyrad, 0.01 to 6 percent of salifying agent, 3 to 12 percent of wetting dispersant, 3 to 15 percent of antifreezing agent, 0.1 to 3 percent of thickening agent, 0.1 to 1 percent of preservative, 0.1 to 1 percent of defoaming agent, 0 to 2 percent of stabilizer, and the balance of water, wherein the pH value is 5.0 to 8.0;

the salifying agent is any one of sodium hydroxide and potassium hydroxide;

the wetting dispersant is one or more of a macromolecular amphiphilic surfactant, polycarboxylate and lignosulfonate.

3. The suspending agent for controlling agricultural pests according to claim 1 or 2, wherein the antifreezing agent is one or more of ethylene glycol, propylene glycol, glycerol and inorganic salts.

4. A suspension for controlling agricultural pests according to claim 1 or 2, wherein the thickener is one or both of magnesium aluminum silicate or xanthan gum.

5. The suspension for controlling agricultural pests according to claim 1 or 2, wherein the preservative is one or more of sodium benzoate, 1, 2-benzisothiazolin-3-one and kefir.

6. A suspending agent for controlling agricultural pests according to claim 1 or 2, wherein the antifoaming agent is an organosilicon antifoaming agent and the stabilizer is hydrochloric acid, sulfuric acid, oxalic acid, benzoic acid, citric acid, glacial acetic acid.

7. A suspension for controlling agricultural pests according to claim 2, wherein the sum of the weight percentages of dinotefuran and tolfenpyrad is 1-50%, preferably the weight ratio of emamectin benzoate to cyantraniliprole is 10:1-1:20.

8. A suspension for controlling agricultural pests according to claim 2, wherein the wetting dispersant is a mixture of a polymeric amphiphilic surfactant, a polycarboxylate and lignin sulfonic acid, preferably the polymeric amphiphilic surfactant is SP-SC29, the polycarboxylate is SP-27001 and the lignin sulfonate is SP-SC3220F; wherein, SP-SC29: SP-27001: SP-SC3220F mass ratio= (1-3): (1-6): (1-3).

9. The method for preparing a suspending agent for controlling agricultural pests according to any one of claims 1 to 8, which is characterized by comprising the steps of:

1) According to the design of the components, mixing a thickener, a preservative and water to prepare a thickener aqueous solution with the concentration of 1-2 wt%, shearing for 30-40 min, standing for more than 24h to obtain a cured thickener aqueous solution for standby;

2) Uniformly mixing a wetting dispersant, an antifreezing agent, a defoaming agent and water to obtain a material 1, wherein the adding amount of the defoaming agent is 30-70% of the total amount of the defoaming agent, and the adding amount of the water is 30-60% of the total amount of the water;

3) Adding a cured thickener aqueous solution, dinotefuran and/or tolfenpyrad raw material into the obtained material 1, shearing 25-30 mm until the materials are uniformly mixed to obtain a material 2, wherein the temperature of the material in the shearing process is not more than 30 ℃; wherein, the addition amount of the cured thickener aqueous solution is 0-40% of the total amount of the thickener aqueous solution; the addition amount of dinotefuran is 0-2% of the total amount;

4) The obtained material 2 is sanded, the grain diameter D90 is controlled to be 2-4 mu m after the sanding, and the material 3 is obtained for standby after the sanding is finished; the sanding temperature is not more than 25 ℃;

5) Mixing the rest dinotefuran, the salifying agent and water, stirring for 1.5-2 h at 1440r/min until the materials are mixed uniformly and react completely to obtain a material 4 for later use; wherein the addition amount of water is 40-70% of the total amount of water, and the mol ratio of the salifying agent to dinotefuran is 1:1; then adding the material 3 into the material 4, shearing for 25-30 min until the materials 5 are obtained after uniform mixing, wherein the grain diameter D90 of the sheared materials 5 is less than or equal to 5 mu m, and the temperature of the materials in the shearing process is not more than 30 ℃;

6) Adding the stabilizer, the residual cured thickener aqueous solution, the residual defoamer and the residual water into the material 5, stirring for 20-25 min until the materials are uniformly mixed, and obtaining the pesticide suspending agent for controlling agricultural pests.

10. Use of a suspension for controlling agricultural pests according to any one of claims 1 to 8 for controlling tea leafhoppers.