Preparation process and application of thiamethoxam water dispersible granules

Abstract

The invention relates to the technical field of biocides, pest repellents or attractants containing organic compounds, and particularly discloses a preparation process and application of thiamethoxam water dispersible granules. The water dispersible granule comprises coated thiamethoxam, a dispersing agent, a wetting agent, a disintegrating agent, filler and water. The invention also provides a preparation method of the composition. Compared with the prior art, the prepared water dispersible particle size has the advantages of being good in dispersity, easy to disintegrate, good in stability, good in deinsectization effect and the like.

Description

Technical Field

[0001] The invention relates to the technical field of biocides, pest repellents or attractants containing organic compounds, and in particular to a preparation process of thiamethoxam water dispersible granules and application thereof. Background Art

[0002] Thiamethoxam is a second-generation nicotine-based insecticide with high efficiency and low toxicity, with a chemical formula of C8H 10 ClN5O3S has stomach poison, contact killing and systemic activity against pests, and is used for foliar spraying and soil root irrigation. After application, it is quickly absorbed and transmitted to various parts of the plant, and has good preventive effects on piercing-sucking pests such as aphids, planthoppers, leafhoppers, whiteflies, etc. As a second-generation nicotine insecticide, thiamethoxam is similar to imidacloprid in terms of its mechanism of action. Both inhibit the receptor activity of related enzymes in the pest body, making the related neural information transmission process unable to be completed, and the pest becomes paralyzed to achieve the insecticidal effect. This neonicotinoid ingredient has three ways of acting in the pest body. The first is direct contact killing. For some larvae of pests, they can be directly killed after contact with thiamethoxam. Secondly, it can kill insects through stomach poisoning. If the liquid sprayed on the surface of the crop is eaten directly by the pest, it will be absorbed through the digestive tract and cause poisoning and death. Finally, it can kill insects through plant systemic absorption. Thiamethoxam can be absorbed by the plant first. When the pest sucks the plant juice, thiamethoxam indirectly enters the pest's body and kills the pest. It is precisely because of its systemic insecticidal action that thiamethoxam has a good preventive effect on some pests with piercing-sucking mouthparts. Suitable crops include rice crops, sugar beets, rapeseed, potatoes, cotton, beans, fruit trees, peanuts, sunflowers, soybeans, tobacco and citrus. It is safe for crops and has no pesticide damage when used at the recommended dose.

[0003] Chinese patent 201410052219.6 provides a multifunctional environmentally friendly thiamethoxam water, which includes, by weight percentage: 1%-5% thiamethoxam, 1%-10% agent A, and 1%-5% functionalizing agent. The agent A is selected from one or more of anionic surfactants containing sulfonic acid groups, anionic surfactants containing sulfuric acid groups, and anionic surfactants containing carboxylic acid groups. Preferably, an agent B accounting for 1%-6% of the total weight of the preparation can also be included. The invention also provides a method for preparing the multifunctional environmentally friendly thiamethoxam water. Experiments have shown that the indoor insecticidal activity of the multifunctional environmentally friendly thiamethoxam water of the present invention is equivalent to that of a thiamethoxam water dispersant of the same concentration. The thiamethoxam water provided by the invention does not contain any organic solvent, has an appearance of a uniform and clear solution, is stable for a long time, and is significantly better than emulsifiable concentrates and other water-based formulations.

[0004] Chinese patent application 202310160163.5 provides a thiamethoxam water dispersible granule, which includes 25% thiamethoxam, 1-6% dispersant, 1-8% wetting agent, 1-10% disintegrant, and filler supplemented to 100% by mass percentage. The invention uses specific dispersants, disintegrants and other auxiliary ingredients to obtain 25% thiamethoxam water dispersible granules with excellent and lasting suspension stability and dispersibility, with a suspension performance of more than 92.5%, and can be effectively stored. It is not easy to agglomerate and precipitate after long-term storage; it disintegrates quickly and delicately in aqueous solution, and can disintegrate completely without dead particles. The 25% thiamethoxam water dispersible granules of the invention have excellent insecticidal effects when used. After 5 days of drug application, the prevention effect can reach more than 90%, and can effectively prevent and control various aphids, leafhoppers, planthoppers, whiteflies, beetle larvae, potato beetles, nematodes, ground beetles, leaf miners and other pests and pests that have developed resistance to various types of chemical pesticides.

[0005] Thiamethoxam is a representative insecticide of the neonicotinoid class and is widely used. However, its poor water solubility limits its application scope. At present, the commonly used dosage forms are mainly water dispersants and suspensions. However, thiamethoxam itself has poor water solubility. Although using water as a dispersion medium reduces pollution, the problem of low utilization rate has not been fundamentally solved. Therefore, the development of a thiamethoxam water dispersant with high utilization rate and good efficacy will have greater application value. Summary of the invention

[0006] In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is to provide a preparation process and application of thiamethoxam water dispersible granules.

[0007] New nicotinoid insecticides have the characteristics of high efficiency, wide insecticide spectrum and low toxicity to mammals. Thiamethoxam belongs to the second generation of neonicotinoid insecticides, occupying 30% of the market share of the entire neonicotinoid drugs, but due to the disadvantages of poor water solubility, short efficacy and low utilization rate. Repeated spraying and excessive use of pesticides cause pollution to the environment and affect human health. Therefore, in the present invention, a coating is obtained by preparing a polymer and assembling it with thiamethoxam, and the interaction between the positively charged tertiary amine in the polymer side chain and the negatively charged nitro group in thiamethoxam can well coat thiamethoxam therein, thereby obtaining a stable coating, and the coated particles obtained after coating can be better dissolved in water due to the small particle size of the polymer, so that the dispersion is better after being prepared into a liquid medicine, which is conducive to plant absorption, and also improves the utilization rate of thiamethoxam, thereby improving the efficacy. In addition, coating thiamethoxam is conducive to reducing drug damage and improving the bioavailability of the drug. The inclusion mode can better prevent and control pests, reduce pesticide residues, reduce environmental pollution, and ensure the sustainable development of agriculture.

[0008] To achieve the above object, the present invention provides a preparation process of thiamethoxam water dispersible granules, comprising the following steps: S1: Mix the coated thiamethoxam, dispersant, wetting agent, disintegrant and filler evenly, grind them, add water and stir for 10-30 minutes; S2: the material obtained by stirring in step S1 is extruded, granulated, dried, and sieved to obtain water dispersible granules.

[0009] The preparation method of the coated thiamethoxam comprises the following steps: X1: 4-8 parts by weight of dimethyl monochlorosilane and 0.1-0.15 parts by weight of palladium carbon (palladium content 5 wt%) are mixed, heated to 40-50°C, and 0.3-0.6 parts by weight of allyl bromoisobutyrate is added under a nitrogen atmosphere and protected from light. The mixture is cooled to room temperature after stirring for 1-2 hours, filtered, and the filtrate is concentrated under reduced pressure to obtain 3-(chlorodimethylsilyl)propyl 2-bromo-2-methylpropionate; X2: 2-3 parts by weight of pentaerythritol and 0.5-1.5 parts by weight of triethylamine are added to 20-40 parts by weight of anhydrous tetrahydrofuran, and the mixture is cooled to 0-5°C and then dropwise added with 2.5-4 parts by weight of 3-(chlorodimethylsilyl)propyl 2-bromo-2-methylpropionate. The mixture is stirred at room temperature for 20-30 hours and then methanol is added to quench the mixture. The residue is concentrated under reduced pressure and then recrystallized from diethyl ether and used in the next step; X3: adding the product of the previous step to 100-300 parts by weight of anhydrous tetrahydrofuran, and then adding 200-300 parts by weight of dimethylaminoethyl methacrylate, and adding 3.3-5.8 parts by weight of copper bromide and 0.5-1.1 parts by weight of pentamethyldiethylenetriamine under a nitrogen atmosphere, heating to 50-65°C and stirring for 6-10 hours, concentrating under reduced pressure to remove the solvent, and then dialyzing with water (Mw < 20000) for 3-5 days, and drying to obtain a coated polymer; X4: Thiamethoxam and the coating polymer are added into 40-80 times volume of water in a weight ratio of 1:1-3, stirred at room temperature for 1-2 hours and then freeze-dried to obtain the coated thiamethoxam.

[0010] Furthermore, the mass ratio of the coated thiamethoxam, dispersant, wetting agent, disintegrant, filler and water is 190-215:1-15:1-18:5-20:5-35:5-20.

[0011] Furthermore, the dispersant is one or a mixture of two or more of a polycarboxylate dispersant, a naphthalenesulfonate dispersant, and an alkylbenzenesulfonate dispersant.

[0012] Furthermore, the wetting agent is one or a mixture of two or more of sodium dodecylbenzene sulfonate, sodium dodecyl sulfate, sodium butylnaphthalene sulfonate, and sodium diisopropylnaphthalene sulfonate.

[0013] Furthermore, the disintegrant is one or a mixture of two or more of sodium carboxymethyl starch, calcium chloride, sodium chloride, sodium carboxymethyl cellulose, and ammonium sulfate.

[0014] Furthermore, the filler is one or a mixture of two or more of kaolin, diatomaceous earth, white carbon black and bentonite.

[0015] Furthermore, the drying is performed at 50-60° C. for 1-2 hours.

[0016] Furthermore, the sieved particle size is 200 mesh.

[0017] The present invention also provides a thiamethoxam water dispersible granule and application thereof. The water dispersible granule is prepared by the above method.

[0018] Beneficial effects of the present invention: 1. Compared with the prior art, the present invention improves the water solubility of thiamethoxam by coating it. The prepared water-dispersible granules have better dispersibility after being prepared into a dispersion liquid, which is beneficial to plant absorption. At the same time, it also improves the utilization rate of thiamethoxam, thereby improving the efficacy.

[0019] 2. Compared with the prior art, the thiamethoxam water dispersible granules of the present invention can better prevent and control insect pests, while reducing pesticide residues, reducing environmental pollution, and ensuring the sustainable development of agriculture. DETAILED DESCRIPTION

[0020] The technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] The present invention is further explained below in conjunction with specific implementation modes.

[0022] Polycarboxylate dispersant, model: SD-819.

[0023] Comparative Example 1 A preparation process of thiamethoxam water dispersible granules comprises the following steps: S1: Mix 70g of thiamethoxam, 10g of SD-819, 15g of sodium dodecyl sulfate, 18g of ammonium sulfate, and 25g of bentonite, grind them evenly, add 20mL of water and stir for 15min; S2: the material obtained by stirring in step S1 is extruded and granulated, then dried at 55° C. for 2 h, and passed through a 200-mesh sieve to obtain water-dispersible granules.

[0024] Example 1 A preparation process of thiamethoxam water dispersible granules comprises the following steps: S1: Mix 210 g of coated thiamethoxam, 10 g of SD-819, 15 g of sodium dodecyl sulfate, 18 g of ammonium sulfate, and 25 g of bentonite, grind them evenly, add 20 mL of water and stir for 15 min; S2: the material obtained by stirring in step S1 is extruded and granulated, then dried at 55° C. for 2 h, and passed through a 200-mesh sieve to obtain water-dispersible granules.

[0025] The preparation method of the coated thiamethoxam comprises the following steps: X1: 4.75 g of dimethyl monochlorosilane and 0.11 g of palladium carbon (palladium content 5 wt%) were mixed, heated to 45 °C, 0.45 g of allyl bromoisobutyrate was added under a nitrogen atmosphere and protected from light, and the mixture was cooled to room temperature after stirring for 2 h. The mixture was filtered and the filtrate was concentrated under reduced pressure to obtain 3-(chlorodimethylsilyl)propyl 2-bromo-2-methylpropionate; X2 Add 2.5 g of pentaerythritol and 1.2 g of triethylamine to 30 mL of anhydrous tetrahydrofuran, cool to 0°C, add 3.5 g of 3-(chlorodimethylsilyl)propyl 2-bromo-2-methylpropionate dropwise, stir at room temperature for 26 h, add methanol to quench, concentrate under reduced pressure, and use the residue for the next step after recrystallization from ether; X3: Add the product of the previous step to 300 mL of anhydrous tetrahydrofuran, then add 200 g of dimethylaminoethyl methacrylate, add 5 g of copper bromide and 1 g of pentamethyldiethylenetriamine under a nitrogen atmosphere, heat to 55 °C and stir for 10 h, concentrate under reduced pressure to remove the solvent, add water and dialyze (Mw < 20000) for 3 days, and dry to obtain a coated polymer; X4: Add 70 g of thiamethoxam and 140 g of the coating polymer into 10 L of water, stir at room temperature for 2 h, and then freeze-dry at 10 Pa, -35°C for 72 h to obtain the coated thiamethoxam.

[0026] Example 2 A preparation process of thiamethoxam water dispersible granules comprises the following steps: S1: Mix 210 g of coated thiamethoxam, 10 g of SD-819, 15 g of sodium dodecyl sulfate, 18 g of ammonium sulfate, and 25 g of bentonite, grind them evenly, add 20 mL of water and stir for 15 min; S2: the material obtained by stirring in step S1 is extruded and granulated, then dried at 55° C. for 2 h, and passed through a 200-mesh sieve to obtain water-dispersible granules.

[0027] The preparation method of the coated thiamethoxam comprises the following steps: 70 g of thiamethoxam and 234 g of β-cyclodextrin were added to 10 L of water, stirred at room temperature for 2 h, and then freeze-dried at 10 Pa, -35°C for 72 h to obtain coated thiamethoxam.

[0028] Example 3 A preparation process of thiamethoxam water dispersible granules comprises the following steps: S1: Mix 210 g of coated thiamethoxam, 5 g of SD-819, 15 g of sodium dodecyl sulfate, 18 g of ammonium sulfate, and 25 g of bentonite, grind them evenly, add 20 mL of water and stir for 15 min; S2: the material obtained by stirring in step S1 is extruded and granulated, then dried at 55° C. for 2 h, and passed through a 200-mesh sieve to obtain water-dispersible granules.

[0029] The preparation method of the coated thiamethoxam comprises the following steps: X1: 4.75 g of dimethyl monochlorosilane and 0.11 g of palladium carbon (palladium content 5 wt%) were mixed, heated to 45 °C, 0.45 g of allyl bromoisobutyrate was added under a nitrogen atmosphere and protected from light, and the mixture was cooled to room temperature after stirring for 2 h. The mixture was filtered and the filtrate was concentrated under reduced pressure to obtain 3-(chlorodimethylsilyl)propyl 2-bromo-2-methylpropionate; X2 Add 2.5 g of pentaerythritol and 1.2 g of triethylamine to 30 mL of anhydrous tetrahydrofuran, cool to 0°C, add 3.5 g of 3-(chlorodimethylsilyl)propyl 2-bromo-2-methylpropionate dropwise, stir at room temperature for 26 h, add methanol to quench, concentrate under reduced pressure, and use the residue for the next step after recrystallization from ether; X3: Add the product of the previous step to 300 mL of anhydrous tetrahydrofuran, then add 200 g of dimethylaminoethyl methacrylate, add 5 g of copper bromide and 1 g of pentamethyldiethylenetriamine under a nitrogen atmosphere, heat to 55 °C and stir for 10 h, concentrate under reduced pressure to remove the solvent, add water and dialyze (Mw < 20000) for 3 days, and dry to obtain a coated polymer; X4: Add 70 g of thiamethoxam and 140 g of the coating polymer into 10 L of water, stir at room temperature for 2 h, and then freeze-dry at 10 Pa, -35°C for 72 h to obtain the coated thiamethoxam.

[0030] Example 4 A preparation process of thiamethoxam water dispersible granules comprises the following steps: S1: Mix 210g of coated thiamethoxam, 15g of SD-819, 15g of sodium dodecyl sulfate, 18g of ammonium sulfate, and 25g of bentonite, grind them evenly, add 20mL of water and stir for 15min; S2: the material obtained by stirring in step S1 is extruded and granulated, then dried at 55° C. for 2 h, and passed through a 200-mesh sieve to obtain water-dispersible granules.

[0031] The preparation method of the coated thiamethoxam comprises the following steps: X1: 4.75 g of dimethyl monochlorosilane and 0.11 g of palladium carbon (palladium content 5 wt%) were mixed, heated to 45 °C, 0.45 g of allyl bromoisobutyrate was added under a nitrogen atmosphere and protected from light, and the mixture was cooled to room temperature after stirring for 2 h. The mixture was filtered and the filtrate was concentrated under reduced pressure to obtain 3-(chlorodimethylsilyl)propyl 2-bromo-2-methylpropionate; X2 Add 2.5 g of pentaerythritol and 1.2 g of triethylamine to 30 mL of anhydrous tetrahydrofuran, cool to 0°C, add 3.5 g of 3-(chlorodimethylsilyl)propyl 2-bromo-2-methylpropionate dropwise, stir at room temperature for 26 h, add methanol to quench, concentrate under reduced pressure, and use the residue for the next step after recrystallization from ether; X3: Add the product of the previous step to 300 mL of anhydrous tetrahydrofuran, then add 200 g of dimethylaminoethyl methacrylate, add 5 g of copper bromide and 1 g of pentamethyldiethylenetriamine under a nitrogen atmosphere, heat to 55 °C and stir for 10 h, concentrate under reduced pressure to remove the solvent, add water and dialyze (Mw < 20000) for 3 days, and dry to obtain a coated polymer; X4: Add 70 g of thiamethoxam and 140 g of the coating polymer into 10 L of water, stir at room temperature for 2 h, and then freeze-dry at 10 Pa, -35°C for 72 h to obtain the coated thiamethoxam.

[0032] Test Example 1 0.3 g and 0.1 g of the coated thiamethoxam prepared in the example were added to 8 mL of water, and the mixture was shaken in a constant temperature shaker at 30 ° C. in the dark for 24 h until the solution reached equilibrium. After microfiltration, the filtrate was appropriately diluted, the content of thiamethoxam was determined, and the solubility and solubility increase factor of thiamethoxam in each inclusion complex were calculated. The operation was repeated 3 times for each substance, and the average value and solubility increase factor were calculated. The solubility increase factor = the solubility of the drug in the inclusion complex / the solubility of the original drug. The specific data are shown in Table 1.

[0033] Table 1 Solubility test results of coated thiamethoxam

[0034] It can be seen from the dissolution test that the original drug of thiamethoxam has poor solubility in water. If water is used as a medium during application, its utilization rate will be greatly affected, thereby greatly shortening the efficacy time and affecting the insecticide effect. In Examples 1 to 4, thiamethoxam is coated with a coating to improve its water solubility. However, since β-cyclodextrin itself has poor water solubility, it is effective to directly coat thiamethoxam as an inclusion compound to improve water solubility. However, the polymer prepared in Examples 1 to 4 is assembled with thiamethoxam to obtain a coating, and the positively charged tertiary amine in the polymer side chain interacts with the negatively charged nitro group in thiamethoxam, so that thiamethoxam can be well coated therein, thereby obtaining a stable coating. Since the particle size of the polymer is small, the coated particles obtained after coating can be better dissolved in water, so the solubilization effect of thiamethoxam is better, greatly improving the solubility of thiamethoxam in water.

[0035] Test Example 2 The water dispersible granules of thiamethoxam prepared in the control example and the embodiment were subjected to a field test for the prevention and control of thrips. The test was conducted in a green onion field with good fertilizer and water conditions. The test period was at the peak period of thrips. The test set up a blank control and 6 treatments in the test group, 4 repetitions, and a total of 24 plots. The field was randomly arranged in blocks. The application dosage was 7.2g / mu, and the spraying was carried out after dilution with water. The control group was sprayed with an equal amount of water. The surviving thrips were investigated 3d and 14d after the application of the pesticide. 15 green onions were investigated at fixed points in each plot, and the number of insects was investigated 4 times in total. The control effect (%) = [1-(the number of live insects before the blank control area × the number of live insects after the drug treatment area) / (the number of live insects after the blank control area × the number of live insects before the drug treatment area)] × 100%, and the final result was averaged.

[0036] Table 2 Results of field efficacy test of thiamethoxam water dispersible granules

[0037] By comparing the control example with the embodiment, it can be found that coating thiamethoxam can well improve the persistence of the drug effect. This may be because in the embodiment, the coating is obtained by assembling the polymer and thiamethoxam, and the positively charged tertiary amine in the polymer side chain interacts with the negatively charged nitro group in thiamethoxam, so that thiamethoxam can be well coated therein, thereby obtaining a stable coating. Since the particle size of the polymer is small, the coated particles obtained after coating can be better dissolved in water, so the dispersion is better after being prepared into a liquid medicine, which is conducive to the absorption of plants, and the utilization rate of thiamethoxam is also improved, thereby improving the drug effect. In Example 2, since β-cyclodextrin itself has poor water solubility, it is effective to directly coat thiamethoxam as an inclusion compound to improve water solubility, so the effect of improving drug effect is not as good as Example 1.

[0038] Polycarboxylates have a large molecular weight and contain functional groups arranged in a "comb-like" manner, which can be adsorbed on the surface of pesticide particles at multiple points to form a good coating layer, providing good steric hindrance protection for the original drug. In addition, polycarboxylates are anionic dispersants, which form a double electric layer after being adsorbed on the original drug particles, allowing different original drug particles to carry the same charge and repel each other, thereby allowing the original drug to be quickly and stably dispersed in water. If the content of polycarboxylates dispersant SD-819 is too high, it will affect the dispersion stability of water-dispersible granules, which may be due to the fact that when the adsorption of the dispersant on the active ingredient of the pesticide exceeds the saturation point, the excess ions in the solution enter the double electric layer, resulting in a decrease in electrostatic repulsion, and self-polymerization may occur between the long-chain molecules of the dispersant, resulting in problems such as agglomeration and flocculation, so the difference in the prevention effect is shown in Examples 1, 3 to 4.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A process for preparing thiamethoxam water dispersible granules, characterized in that: The steps include: S1: Mix the coated thiamethoxam, dispersant, wetting agent, disintegrant and filler evenly, grind them, add water and stir for 10-30 minutes; S2: the material obtained by stirring in step S1 is extruded, granulated, dried, and sieved to obtain water dispersible granules.

2. The preparation process according to claim 1, characterized in that: The method for preparing the coated thiamethoxam comprises the following steps: X1: Mix dimethyl monochlorosilane and palladium carbon, heat to 40-50°C, add allyl bromoisobutyrate in a dark and nitrogen atmosphere, stir for 1-2 hours, then cool to room temperature, filter, and concentrate the filtrate under reduced pressure to obtain 3-(chlorodimethylsilyl)propyl 2-bromo-2-methylpropionate; X2: Pentaerythritol and triethylamine were added to anhydrous tetrahydrofuran, and the temperature was lowered to 0-5°C, and 2-bromo-2-methylpropionic acid 3-(chlorodimethylsilyl)propyl ester was added dropwise, and the mixture was stirred at room temperature for 20-30 hours, and then methanol was added to quench the mixture. After concentrating under reduced pressure, the residue was recrystallized from ether and used in the next step; X3: The product of the previous step is added to anhydrous tetrahydrofuran, and then dimethylaminoethyl methacrylate is added. In a nitrogen atmosphere, copper bromide and pentamethyldiethylenetriamine are added, and the mixture is heated to 50-65°C and stirred for 6-10 hours. The mixture is concentrated under reduced pressure to remove the solvent and dialyzed with water (Mw < 20,000) for 3-5 days. The coated polymer is obtained after drying. X4: Add thiamethoxam and the coating polymer into water, stir at room temperature for 1-2 hours and then freeze-dry to obtain the coated thiamethoxam.

3. The preparation process according to claim 1, characterized in that: The mass ratio of the coated thiamethoxam, dispersant, wetting agent, disintegrant, filler and water is 190-215:1-15:1-18:5-20:5-35:5-20.

4. The preparation process according to claim 1, characterized in that: The dispersant is one or a mixture of two or more of a polycarboxylate dispersant, a naphthalenesulfonate dispersant and an alkylbenzenesulfonate dispersant.

5. The preparation process according to claim 1, characterized in that: The wetting agent is one of sodium dodecylbenzene sulfonate, sodium dodecyl sulfate, sodium butylnaphthalene sulfonate, sodium diisopropylnaphthalene sulfonate, or a mixture of two or more thereof.

6. The preparation process according to claim 1, characterized in that: The disintegrant is one or a mixture of two or more of sodium carboxymethyl starch, calcium chloride, sodium chloride, sodium carboxymethyl cellulose and ammonium sulfate.

7. The preparation process according to claim 1, characterized in that: The filler is one or a mixture of two or more of kaolin, diatomaceous earth, white carbon black and bentonite.

8. The preparation process according to claim 1, characterized in that: The drying step is performed at 50-60° C. for 1-2 hours; and the sieved particle size is 200 mesh.

9. A thiamethoxam water dispersible granule, characterized in that: Prepared by the method according to any one of claims 1 to 8.

10. Use of the water dispersible granules according to claim 9 in the field of pesticides.

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