Thiamethoxam water dispersible granule and production process thereof

Abstract

The invention provides thiamethoxam water dispersible granules and a production process thereof, and belongs to the technical field of pesticide preparation. The production process comprises the following steps: modifying methyl methacrylate; preparing an anti-ultraviolet carrier; loading eugenol; and preparing the water dispersible granules. The water dispersible granule is prepared by mixing the uvioresistant carrier loaded with eugenol with thiamethoxam, the dispersing agent, the wetting agent, the disintegrating agent and the binder, when eugenol and thiamethoxam are combined for use, the pest killing effect can be synergistically enhanced, and in addition, eugenol can bypass the resistance mechanism of pests to thiamethoxam, so that the pest killing effect is improved. Even if pests have certain tolerance to neurotoxicity of thiamethoxam, eugenol can still play a role by destroying cell membrane structures and respiratory systems of the pests, so that the resistance of the pests is broken, and the overall insecticidal effect of the prepared water dispersible granule is enhanced.

Description

Technical Field

[0001] The invention relates to the technical field of pesticide preparation, and in particular to thiamethoxam water dispersible granules and a production process thereof. Background Art

[0002] Thiamethoxam is a highly effective, broad-spectrum, systemic insecticide that has excellent control effects on a variety of pests and is widely used in agricultural production. However, traditional thiamethoxam preparations such as emulsifiable concentrates and wettable powders have some shortcomings. The emulsifiable concentrate formulation contains a large amount of organic solvents, which not only pollutes the environment, but also poses safety hazards during storage and transportation; wettable powders are prone to dust flying, affecting the health of operators, and their dispersibility and suspension stability in water are not ideal, which can easily lead to uneven application and affect the control effect; water-dispersible granules, as an environmentally friendly pesticide formulation, have the advantages of no dust pollution, good fluidity, easy measurement and use, rapid dispersion in water and high stability.

[0003] However, there are still some problems with the thiamethoxam water dispersible granules on the market. For example, when the ambient temperature and humidity change or after being placed for a long time, the surface energy of the particles changes due to the properties of the active ingredients themselves or the interaction with other adjuvants, which makes the particles easy to agglomerate. When the agglomerated particles are dispersed in water, they cannot be dispersed quickly and evenly, which will affect the use effect of the agent; and in actual use, when the suspended particles are uneven in size, large particles may settle quickly, and small particles may gather together, so that the agent cannot be evenly distributed in the application area, resulting in pests in some areas cannot be effectively controlled, while the concentration of the agent in other areas is too high, which not only wastes the agent, but also may cause damage to crops; in addition, during the long-term use of single chemical pesticides, many pests gradually develop resistance to commonly used chemical pesticides. For example, some pests reduce their sensitivity to single-action mechanism pesticides through gene mutations or physiological adaptation mechanisms, which makes the original effective pesticide dosage continue to increase, which not only increases production costs, but also brings greater risks to the environment and agricultural product safety.

[0004] Therefore, it is necessary to propose a water-dispersible thiamethoxam granule with good dispersibility, good suspension and comprehensive insecticide and a production process thereof, so as to improve the insecticide effect and reduce waste. Summary of the invention

[0005] In view of the shortcomings of the prior art, the object of the present invention is to provide a thiamethoxam water dispersible granule and a production process thereof.

[0006] A production process of thiamethoxam water dispersible granules comprises the following steps: S1: Modified methyl methacrylate Dissolving and mixing methyl methacrylate and cystamine respectively, adding triethylamine to react, preparing aminated methyl methacrylate, and then adding to a mixed modification liquid prepared from aspartic acid, N-hydroxysulfosuccinyl and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride to react, preparing modified methyl methacrylate; S2: Preparation of UV-resistant carrier The whey protein powder is dissolved, and then the modified methyl methacrylate, N,N′-methylenebisacrylamide and potassium persulfate are added to react, and then 1,5-glutaraldehyde is added to continue the reaction, and then the powder is soaked in anhydrous ethanol and deionized water, vacuum freeze-dried and ground to obtain an anti-ultraviolet carrier; S3: Loaded eugenol Add eugenol to anhydrous ethanol at a solid-liquid ratio of 1g: (65-75) mL, stir thoroughly to dissolve, then add the above-mentioned anti-ultraviolet carrier at a solid-liquid ratio of 1g: (15-25) mL, stir thoroughly to disperse, pour into a mold, cure at room temperature for 20-24 hours, and then dry to constant weight to obtain eugenol-loaded powder; S4: Preparation of water dispersible granules Thiamethoxam, the above-mentioned eugenol-loaded powder, a dispersant, a wetting agent, a disintegrant and a binder are mixed and pulverized, and then mixed with water to form granules, and then dried and sieved to obtain water-dispersible granules.

[0007] Furthermore, S1 specifically includes the following steps: S1.1: Dissolve methyl methacrylate and cystamine in dichloromethane at a solid-liquid ratio of 1 g: (40-50) mL, respectively, and stir thoroughly to dissolve to obtain a methyl methacrylate solution and a cystamine solution; S1.2: Add the above cystamine solution to the above methyl methacrylate solution in a volume ratio of 1:(8-10), stir and mix thoroughly, then add 0.2-0.4wt% triethylamine, and heat under reflux at 60-80°C for 4-6h, cool naturally to room temperature, wash, dry and distill under reduced pressure to obtain aminated methyl methacrylate; S1.3: Dissolve aspartic acid in dimethyl sulfoxide at a solid-liquid ratio of 1 g: (10-20) mL, then add N-hydroxysulfosuccinyl and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, stir and react for 1-2 hours to obtain a mixed modified liquid; S1.4: Add the above-mentioned aminated methyl methacrylate to the above-mentioned mixed modified liquid, stir and react at 40-50°C for 12-14h, cool, dialyze, wash and dry to obtain modified methyl methacrylate.

[0008] Furthermore, S2 specifically includes the following steps: S2.1: Add whey protein powder to 0.1 mol / L sodium hydroxide solution at a solid-liquid ratio of 1 g: (15-25) mL, stir thoroughly to dissolve, and obtain a whey protein solution; S2.2: Under a nitrogen atmosphere, add the modified methyl methacrylate obtained in step S1.4 to the whey protein solution while stirring, and heat to 50-60°C, then add N,N′-methylenebisacrylamide and potassium persulfate, and stir to react for 40-50 minutes to obtain a precursor solution; S2.3: Add 1,5-glutaraldehyde to the above precursor solution, stir and keep warm for 30-40 minutes, and keep warm and stand for 6-8 hours. After cooling, transfer to anhydrous ethanol and soak for 18-20 hours, then transfer to deionized water and soak for 18-20 hours. After vacuum freeze drying and grinding, obtain an anti-UV carrier.

[0009] Furthermore, S4 specifically includes the following steps: S4.1: mixing thiamethoxam, the eugenol-loaded powder obtained in step S3, a dispersant, a wetting agent, a disintegrant and a binder, and ultrafine grinding to obtain a mixed powder; S4.2: Add water to the above mixed powder, mix thoroughly, place in an extruder, perform extrusion granulation, dry at 40-60°C to constant weight, and pass through a 100-200 mesh sieve to obtain water dispersible granules.

[0010] Furthermore, the mass ratios of N-hydroxysulfosuccinyl and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride to aspartic acid are 1:(1.1-1.3) and 1:(2-3), respectively.

[0011] Furthermore, the molar ratio of aminated methyl methacrylate to aspartic acid is 1:(1.1-1.2).

[0012] Furthermore, the volume ratio of modified methyl methacrylate to whey protein solution is 1:(5-6), and the mass ratios of N,N′-methylenebisacrylamide, potassium persulfate and 1,5-glutaraldehyde to whey protein powder are 1:(3-4), 1:(10-12) and 1:(1.3-1.5), respectively.

[0013] Furthermore, the water-dispersible granules include, by mass percentage, 10-20% thiamethoxam, 3-5% dispersant, 1-3% wetting agent, 1-2% disintegrant and 0.1-0.5% binder, and the balance is eugenol-loaded powder; wherein the dispersant is one or more of sodium polycarboxylate, alkyl polyoxyethylene ether sulfonate or lignin sulfonate, the wetting agent is one or more of alkyl naphthalene sulfonate, acyl glutamate, fatty alcohol ethoxylate or fatty alcohol polyoxyethylene ether, the disintegrant is one or more of urea, sodium sulfate, calcium sulfate and sodium bicarbonate, and the binder is one or more of polyethylene glycol, carboxymethyl cellulose, polyvinyl alcohol, dextrin or xanthan gum.

[0014] Furthermore, a thiamethoxam water dispersible granule is prepared by any of the above-mentioned production processes for the thiamethoxam water dispersible granules.

[0015] Compared with the prior art, the present invention has at least the following beneficial effects: 1. The water dispersible granules of the present invention use thiamethoxam and eugenol as main insecticidal ingredients, and are prepared by mixing eugenol with thiamethoxam, a dispersant, a wetting agent, a disintegrant and a binder after loading thiamethoxam on an anti-ultraviolet carrier. Eugenol mainly acts on the cell membrane and respiratory system of insects, while thiamethoxam mainly attacks the nervous system of insects, and selectively binds to the nicotinic acetylcholine receptors on the post-neural membrane of insects, causing continuous depolarization of insect nerve cells, causing disorder in nerve signals. When the two are used in combination, thiamethoxam interferes with the conduction of nerve signals of insects, causing When insects show paralysis symptoms, eugenol can simultaneously destroy the insect's cell membrane and accelerate the insect's death process. This multi-target attack method is more comprehensive than a single agent and can kill pests more effectively. Moreover, when used in combination with thiamethoxam, eugenol can bypass the pest's resistance mechanism to thiamethoxam. Even if the pest has developed a certain tolerance to the neurotoxicity of thiamethoxam, eugenol can still work by destroying the pest's cell membrane structure and respiratory system, thereby breaking the pest's resistance and enhancing the overall insecticidal effect of the prepared water-dispersible granules.

[0016] 2. The present invention is to first dissolve methyl methacrylate and cystamine separately, then mix them and carry out an amination reaction under the catalysis of triethylamine, so that one end of cystamine is grafted onto methyl methacrylate, and then, under the catalysis of N-hydroxysulfosuccinyl and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, graft aspartic acid onto the other end of cystamine. Since aspartic acid contains hydrophilic groups carboxyl and amino in its molecular structure, when it is grafted onto the other end of cystamine, the carboxyl can ionize hydrogen ions in water to generate negatively charged carboxylate ions, and the amino can be protonated to form positively charged ammonium ions. There are strong electrostatic interactions and hydrogen bonding between these ionized groups and water molecules, thereby significantly improving the overall solubility and affinity in water, thereby achieving the effect of hydrophilic modification of methyl methacrylate, which is beneficial to improving the dispersibility of the anti-ultraviolet carrier in water, and further helping the water-dispersible granules to be stably suspended in water.

[0017] 3. The present invention uses potassium persulfate as an initiator to initiate a polymerization reaction of whey protein, modified methyl methacrylate, N,N′-methylenebisacrylamide and 1,5-glutaraldehyde to prepare an anti-ultraviolet carrier with a three-dimensional network structure. After the anti-ultraviolet carrier is used to load eugenol, on the one hand, the chemical bonds and structure of the carrier can scatter ultraviolet rays, thereby reducing the direct irradiation of ultraviolet rays on eugenol. On the other hand, the chemical groups in the modified methyl methacrylate will undergo transitions under the irradiation of ultraviolet rays, absorb ultraviolet energy, and release it in other forms, thereby playing a dual protective role, effectively reducing the amount of eugenol decomposed by light after the water-dispersible granules are sprayed, and achieving the purpose of effectively improving the insecticidal effect of the water-dispersible granules. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings, which are incorporated herein and constitute a part of the specification, illustrate embodiments of the present disclosure and, together with the description, further serve to explain the principles of the present disclosure and to enable those skilled in the relevant art to make and use the present disclosure.

[0019] Figure 1 This is a production process flow chart of the thiamethoxam water dispersible granules used in the embodiments of the present invention. DETAILED DESCRIPTION

[0020] The thiamethoxam water dispersible granules and the production process thereof provided by the present invention are described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] Example 1 A production process of thiamethoxam water dispersible granules, such as Figure 1 As shown, the following steps are included: S1: Modified methyl methacrylate S1.1: Dissolve methyl methacrylate and cystamine in dichloromethane at a solid-liquid ratio of 1 g:40 mL, respectively, and stir thoroughly to dissolve to obtain a methyl methacrylate solution and a cystamine solution; S1.2: Add the cystamine solution to the methyl methacrylate solution at a volume ratio of 1:8, stir and mix thoroughly, then add 0.2 wt % triethylamine, heat and reflux at 60° C. for 4 h, cool naturally to room temperature, wash, dry and distill under reduced pressure to obtain aminated methyl methacrylate; S1.3: Dissolve aspartic acid in dimethyl sulfoxide at a solid-liquid ratio of 1 g:10 mL, then add N-hydroxysulfosuccinyl and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and stir to react for 1 h to obtain a mixed modified liquid, wherein the mass ratios of N-hydroxysulfosuccinyl and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride to aspartic acid are 1:1.1 and 1:2, respectively; S1.4: adding the above-mentioned aminated methyl methacrylate to the above-mentioned mixed modified solution, stirring and reacting at 40°C for 12 hours, cooling, dialyzing, washing and drying to obtain modified methyl methacrylate, wherein the molar ratio of aminated methyl methacrylate to aspartic acid is 1:1.1; S2: Preparation of UV-resistant carrier S2.1: Add whey protein powder into 0.1 mol / L sodium hydroxide solution at a solid-liquid ratio of 1 g:15 mL, stir thoroughly to dissolve, and obtain a whey protein solution; S2.2: Under a nitrogen atmosphere, add the modified methyl methacrylate obtained in step S1.4 to the above whey protein solution while stirring, and heat to 50°C, then add N,N′-methylenebisacrylamide and potassium persulfate, and stir and react for 40 minutes to obtain a precursor solution, wherein the volume ratio of modified methyl methacrylate to whey protein solution is 1:5, the mass ratio of N,N′-methylenebisacrylamide to whey protein powder is 1:3, and the mass ratio of potassium persulfate to whey protein powder is 1:10; S2.3: Add 1,5-glutaraldehyde to the precursor solution, keep warm and stir for 30 minutes, keep warm and stand for 6 hours, transfer to anhydrous ethanol after cooling, soak for 18 hours, and then transfer to deionized water, soak for 18 hours, and obtain an anti-ultraviolet carrier by vacuum freeze drying and grinding, wherein the mass ratio of 1,5-glutaraldehyde to whey protein powder is 1:1.3; S3: Loaded eugenol Add eugenol to anhydrous ethanol at a solid-liquid ratio of 1g:65mL, stir thoroughly to dissolve, then add the above-mentioned anti-ultraviolet carrier at a solid-liquid ratio of 1g:15mL, stir thoroughly to disperse, pour into a mold, cure at room temperature for 20h, and then dry to constant weight to obtain eugenol-loaded powder; S4: Preparation of water dispersible granules S4.1: 10% thiamethoxam, 84.9% eugenol-loaded powder obtained in step S3, 3% dispersant, 1% wetting agent, 1% disintegrant and 0.1% binder are mixed uniformly by mass percentage, and ultrafinely ground to obtain a mixed powder; S4.2: Add water to the above mixed powder, mix thoroughly, place in an extruder, perform extrusion granulation, dry at 40°C to constant weight, and pass through a 100-mesh sieve to obtain water-dispersible granules.

[0022] Example 2 A production process of thiamethoxam water dispersible granules, such as Figure 1 As shown, the following steps are included: S1: Modified methyl methacrylate S1.1: Dissolve methyl methacrylate and cystamine in dichloromethane at a solid-liquid ratio of 1 g:45 mL, respectively, and stir thoroughly to dissolve to obtain a methyl methacrylate solution and a cystamine solution; S1.2: Add the cystamine solution to the methyl methacrylate solution at a volume ratio of 1:9, stir and mix thoroughly, then add 0.3 wt % triethylamine, heat and reflux at 70° C. for 5 h, cool naturally to room temperature, wash, dry and distill under reduced pressure to obtain aminated methyl methacrylate; S1.3: Dissolve aspartic acid in dimethyl sulfoxide at a solid-liquid ratio of 1 g:15 mL, then add N-hydroxysulfosuccinyl and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and stir to react for 1.5 h to obtain a mixed modified liquid, wherein the mass ratios of N-hydroxysulfosuccinyl and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride to aspartic acid are 1:1.2 and 1:2.5, respectively; S1.4: adding the above-mentioned aminated methyl methacrylate to the above-mentioned mixed modified solution, stirring and reacting at 45°C for 13 hours, cooling, dialyzing, washing and drying to obtain modified methyl methacrylate, wherein the molar ratio of aminated methyl methacrylate to aspartic acid is 1:1.15; S2: Preparation of UV-resistant carrier S2.1: Add whey protein powder into 0.1 mol / L sodium hydroxide solution at a solid-liquid ratio of 1 g:20 mL, stir thoroughly to dissolve, and obtain a whey protein solution; S2.2: Under a nitrogen atmosphere, add the modified methyl methacrylate obtained in step S1.4 to the above whey protein solution while stirring, and heat to 55°C, then add N,N′-methylenebisacrylamide and potassium persulfate, and stir and react for 45 minutes to obtain a precursor solution, wherein the volume ratio of modified methyl methacrylate to whey protein solution is 1:5.5, the mass ratio of N,N′-methylenebisacrylamide to whey protein powder is 1:3.5, and the mass ratio of potassium persulfate to whey protein powder is 1:11; S2.3: Add 1,5-glutaraldehyde to the precursor solution, keep warm and stir for 35 minutes, keep warm and stand for 7 hours, transfer to anhydrous ethanol after cooling, soak for 19 hours, and then transfer to deionized water, soak for 19 hours, and obtain an anti-ultraviolet carrier by vacuum freeze drying and grinding, wherein the mass ratio of 1,5-glutaraldehyde to whey protein powder is 1:1.4; S3: Loaded eugenol Add eugenol to anhydrous ethanol at a solid-liquid ratio of 1g:70mL, stir thoroughly to dissolve, then add the above-mentioned anti-ultraviolet carrier at a solid-liquid ratio of 1g:20mL, stir thoroughly to disperse, pour into a mold, cure at room temperature for 22h, and then dry to constant weight to obtain eugenol-loaded powder; S4: Preparation of water dispersible granules S4.1: 15% thiamethoxam, 77.2% eugenol-loaded powder obtained in step S3, 4% dispersant, 2% wetting agent, 1.5% disintegrant and 0.3% binder are mixed uniformly by mass percentage, and ultrafinely ground to obtain a mixed powder; S4.2: Add water to the above mixed powder, mix thoroughly, place in an extruder, perform extrusion granulation, dry at 50°C to constant weight, and pass through a 150-mesh sieve to obtain water-dispersible granules.

[0023] Example 3 A production process of thiamethoxam water dispersible granules, such as Figure 1 As shown, the following steps are included: S1: Modified methyl methacrylate S1.1: Dissolve methyl methacrylate and cystamine in dichloromethane at a solid-liquid ratio of 1 g:50 mL, respectively, and stir thoroughly to dissolve to obtain a methyl methacrylate solution and a cystamine solution; S1.2: Add the cystamine solution to the methyl methacrylate solution at a volume ratio of 1:10, stir and mix thoroughly, then add 0.4 wt % of triethylamine, heat and reflux at 80° C. for 6 h, cool naturally to room temperature, wash, dry and distill under reduced pressure to obtain aminated methyl methacrylate; S1.3: Dissolve aspartic acid in dimethyl sulfoxide at a solid-liquid ratio of 1 g:20 mL, then add N-hydroxysulfosuccinyl and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and stir to react for 2 h to obtain a mixed modified liquid, wherein the mass ratios of N-hydroxysulfosuccinyl and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride to aspartic acid are 1:1.3 and 1:3, respectively; S1.4: adding the above-mentioned aminated methyl methacrylate to the above-mentioned mixed modified solution, stirring and reacting at 50°C for 14 hours, cooling, dialyzing, washing and drying to obtain modified methyl methacrylate, wherein the molar ratio of aminated methyl methacrylate to aspartic acid is 1:1.2; S2: Preparation of UV-resistant carrier S2.1: Add whey protein powder into 0.1 mol / L sodium hydroxide solution at a solid-liquid ratio of 1 g:25 mL, stir thoroughly to dissolve, and obtain a whey protein solution; S2.2: Under a nitrogen atmosphere, add the modified methyl methacrylate obtained in step S1.4 to the above whey protein solution while stirring, and heat to 60°C, then add N,N′-methylenebisacrylamide and potassium persulfate, and stir and react for 50 minutes to obtain a precursor solution, wherein the volume ratio of modified methyl methacrylate to whey protein solution is 1:6, and the mass ratios of N,N′-methylenebisacrylamide to whey protein powder are 1:4 and the mass ratio of potassium persulfate to whey protein powder is 1:12; S2.3: Add 1,5-glutaraldehyde to the precursor solution, keep warm and stir for 40 minutes, keep warm and stand for 6-8 hours, transfer to anhydrous ethanol after cooling, soak for 20 hours, and then transfer to deionized water, soak for 20 hours, and obtain an anti-ultraviolet carrier by vacuum freeze drying and grinding, wherein the mass ratio of 1,5-glutaraldehyde to whey protein powder is 1:1.5; S3: Loaded eugenol Add eugenol to anhydrous ethanol at a solid-liquid ratio of 1g:75mL, stir thoroughly to dissolve, then add the above-mentioned anti-ultraviolet carrier at a solid-liquid ratio of 1g:25mL, stir thoroughly to disperse, pour into a mold, cure at room temperature for 24h, and then dry to constant weight to obtain eugenol-loaded powder; S4: Preparation of water dispersible granules S4.1: 20% thiamethoxam, 69.5% eugenol-loaded powder obtained in step S3, 5% dispersant, 3% wetting agent, 2% disintegrant and 0.5% binder are mixed uniformly by mass percentage, and ultrafinely ground to obtain a mixed powder; S4.2: Add water to the above mixed powder, mix thoroughly, place in an extruder, perform extrusion granulation, dry at 60°C to constant weight, and pass through a 200-mesh sieve to obtain water-dispersible granules.

[0024] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that the eugenol-containing powder in step S4.1 is removed and thiamethoxam is added, wherein the amount of thiamethoxam added is equal to the eugenol content in the removed eugenol-containing powder.

[0025] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that the thiamethoxam in step S4.1 is removed, and eugenol-loaded powder is added, wherein the eugenol content in the eugenol-loaded powder is equal to the removed thiamethoxam content.

[0026] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that step S1 is removed, and the modified methyl methacrylate in step S2.2 is replaced by an equal amount of methyl methacrylate.

[0027] Comparative Example 4 The difference between this comparative example 4 and example 1 is that step S1-3 is removed, and the eugenol-loaded powder in step S4.1 is replaced with eugenol, wherein the amount of eugenol added is equal to the eugenol content in the eugenol-loaded powder added in step S4.1 of example 1.

[0028] Test Case Test 1: Field efficacy test on soybean aphids Test method: refer to the "Guidelines for Field Efficacy Tests of Pesticides Part 27: Pesticides for Control of Cruciferous Vegetable Aphids", with soybean aphids as the control target, and the test field is 100m 2 , were randomly divided into 5 groups, namely, Example 1 group, Example 2 group, Example 3 group, Comparative Example 1 group and Comparative Example 2 group, each group had 20m 2 Before spraying, the number of larvae of each age was counted for each group as the insect population base. Then, the drugs were sprayed on each group for prevention and control. The number of remaining live insects was counted on the 1st, 3rd and 7th day after spraying, and the insect population reduction rate was calculated using the following formula: Insect population reduction rate = [(number of live insects before spraying water dispersible granules - number of live insects after spraying water dispersible granules) / number of live insects before spraying water dispersible granules] × 100%, the results are shown in Table 1; Statistical counting method: adopt the 5-point sampling method, calculate the average value of the insect population of the 5 sampling points, and count the insect population base of each group; Application situation: Example 1 group: spray the water dispersible granules prepared in Example 1, the dosage per mu is 5g / mu, and the spray is diluted with 3L / mu of water; Example 2 group: spray the water dispersible granules prepared in Example 2, the dosage per mu is 5g / mu, and the spray is diluted with 3L / mu of water; Example 3 group: spray the water dispersible granules prepared in Example 3, the dosage per mu is 5g / mu, and the spray is diluted with 3L / mu of water; Comparative Example 1: spray the water dispersible granules prepared in Comparative Example 1, the dosage per mu is 5g / mu, and the spray is diluted with 3L / mu of water; Comparative Example 2 group: spray the water dispersible granules prepared in Comparative Example 2, the dosage per mu is 5g / mu, and the spray is diluted with 3L / mu of water.

[0029] Table 1: Comparison of efficacy test results of each group of water dispersible granules

[0030] As can be seen from Table 1, the control effects of the water dispersible granules made of thiamethoxam alone on soybean aphids in Comparative Example 1 were about 70.5%, 82.2% and 88.7% respectively 1 day, 3 days and 7 days after spraying, which were lower than those of the water dispersible granules made of thiamethoxam and eugenol in Examples 1-3. The control effects of the water dispersible granules made of eugenol alone on soybean aphids in Comparative Example 2 were 54.6%, 61.3% and 67.9% respectively 1 day, 3 days and 7 days after spraying, which were also lower than those of the water dispersible granules made of thiamethoxam and eugenol in Examples 1-3. The results are both lower than the water dispersible granules prepared by using thiamethoxam and eugenol at the same time in Examples 1-3. It can be seen that the water dispersible granules of the present invention use thiamethoxam and eugenol as main insecticidal ingredients. When the two are used in combination, insects have to bear the physiological pressure caused by the damage to the nervous system on the one hand, and have to deal with the damage of the respiratory system of the cell membrane by eugenol on the other hand, making it more difficult for the pests to adapt to the combined effect, thereby synergistically enhancing the killing effect on the pests, breaking the resistance of the pests, and enhancing the overall insecticidal effect of the prepared water dispersible granules.

[0031] Test 2: The suspension rate test was carried out according to the method specified in GB / T14825-2006 "Determination of Suspension Rate of Pesticides". The results are shown in Table 2.

[0032] Table 2: Comparison of the suspension rate test results of the water dispersible granules prepared in Examples 1-3 and Comparative Example 3

[0033] As can be seen from Table 2, in Comparative Example 3, methyl methacrylate is not modified, but methyl methacrylate is directly reacted with whey protein to prepare an anti-ultraviolet carrier, and then eugenol is loaded with the carrier. The suspension rate of the obtained water-dispersible granules is about 79.6%, which is lower than the suspension rate of the water-dispersible granules obtained after methyl methacrylate is modified in Examples 1-3. That is to say, the dispersibility of the water-dispersible granules obtained in Comparative Example 3 is poorer than that of Examples 1-3. It can be seen that by first dissolving methyl methacrylate and cystamine separately, then mixing and performing an amination reaction under the catalysis of triethylamine, one end of cystamine is grafted onto methyl methacrylate, and then aspartic acid is grafted onto the other end of cystamine under the catalysis of N-hydroxysulfosuccinyl and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, so as to achieve the effect of hydrophilic modification of methyl methacrylate, which is beneficial to improve the dispersibility of the anti-ultraviolet carrier in water, and further helps the water-dispersible granules to be stably suspended in water.

[0034] Test 3: The eugenol powder prepared in Examples 1-3 and the eugenol used in Comparative Example 4 were placed in beakers containing 250 mL of 70% ethanol solution, respectively. Under the same experimental conditions, they were irradiated with ultraviolet light. The concentration of eugenol in the beaker was measured every 10 minutes, and the degradation rate of eugenol after 100 minutes of irradiation was calculated. The results are shown in Table 3.

[0035] Table 3: Comparison of the test results of the anti-ultraviolet performance of the eugenol-containing powders obtained in Examples 1-3 and Comparative Example 4

[0036] As can be seen from Table 3, when eugenol is not loaded in Comparative Example 4, the degradation rate of eugenol after 100 minutes of ultraviolet light irradiation is about 89.6%, which is significantly higher than that of Examples 1-3. It can be seen that by using potassium persulfate as an initiator to initiate a polymerization reaction of whey protein, modified methyl methacrylate, N,N′-methylenebisacrylamide and 1,5-glutaraldehyde to prepare an anti-ultraviolet carrier with a three-dimensional network structure, after eugenol is loaded with the anti-ultraviolet carrier, the amount of eugenol decomposed by light after the water-dispersible granules are sprayed can be effectively reduced, thereby achieving the purpose of effectively improving the insecticidal effect of the water-dispersible granules.

[0037] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A production process for thiamethoxam water dispersible granules, characterized in that: The steps include: S1: Modified methyl methacrylate Dissolving and mixing methyl methacrylate and cystamine respectively, adding triethylamine to react, preparing aminated methyl methacrylate, and then adding to a mixed modification liquid prepared from aspartic acid, N-hydroxysulfosuccinyl and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride to react, preparing modified methyl methacrylate; S2: Preparation of UV-resistant carrier The whey protein powder is dissolved, and then the modified methyl methacrylate, N,N′-methylenebisacrylamide and potassium persulfate are added to react, and then 1,5-glutaraldehyde is added to continue the reaction, and then the powder is soaked in anhydrous ethanol and deionized water, vacuum freeze-dried and ground to obtain an anti-ultraviolet carrier; S3: Loaded eugenol Add eugenol to anhydrous ethanol at a solid-liquid ratio of 1g: (65-75) mL, stir thoroughly to dissolve, then add the above-mentioned anti-ultraviolet carrier at a solid-liquid ratio of 1g: (15-25) mL, stir thoroughly to disperse, pour into a mold, cure at room temperature for 20-24 hours, and then dry to constant weight to obtain eugenol-loaded powder; S4: Preparation of water dispersible granules Thiamethoxam, the above-mentioned eugenol-loaded powder, a dispersant, a wetting agent, a disintegrant and a binder are mixed and pulverized, and then mixed with water to form granules, and then dried and sieved to obtain water-dispersible granules.

2. The production process of thiamethoxam water dispersible granules according to claim 1, characterized in that: S1 includes the following steps: S1.1: Dissolve methyl methacrylate and cystamine in dichloromethane at a solid-liquid ratio of 1 g: (40-50) mL, respectively, and stir thoroughly to dissolve to obtain a methyl methacrylate solution and a cystamine solution; S1.2: Add the above cystamine solution to the above methyl methacrylate solution in a volume ratio of 1:(8-10), stir and mix thoroughly, then add 0.2-0.4wt% triethylamine, and heat under reflux at 60-80°C for 4-6h, cool naturally to room temperature, wash, dry and distill under reduced pressure to obtain aminated methyl methacrylate; S1.3: Dissolve aspartic acid in dimethyl sulfoxide at a solid-liquid ratio of 1 g: (10-20) mL, then add N-hydroxysulfosuccinyl and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, stir and react for 1-2 hours to obtain a mixed modified liquid; S1.4: Add the above-mentioned aminated methyl methacrylate to the above-mentioned mixed modified liquid, stir and react at 40-50°C for 12-14h, cool, dialyze, wash and dry to obtain modified methyl methacrylate.

3. The production process of thiamethoxam water dispersible granules according to claim 2, characterized in that: S2 includes the following steps: S2.1: Add whey protein powder to 0.1 mol / L sodium hydroxide solution at a solid-liquid ratio of 1 g: (15-25) mL, stir thoroughly to dissolve, and obtain a whey protein solution; S2.2: Under a nitrogen atmosphere, add the modified methyl methacrylate obtained in step S1.4 to the whey protein solution while stirring, and heat to 50-60°C, then add N,N′-methylenebisacrylamide and potassium persulfate, and stir to react for 40-50 minutes to obtain a precursor solution; S2.3: Add 1,5-glutaraldehyde to the above precursor solution, stir and keep warm for 30-40 minutes, and keep warm and stand for 6-8 hours. After cooling, transfer to anhydrous ethanol and soak for 18-20 hours, then transfer to deionized water and soak for 18-20 hours. After vacuum freeze drying and grinding, obtain an anti-UV carrier.

4. The production process of thiamethoxam water dispersible granules according to claim 3, characterized in that: S4 includes the following steps: S4.1: mixing thiamethoxam, the eugenol-loaded powder obtained in step S3, a dispersant, a wetting agent, a disintegrant and a binder, and ultrafine grinding to obtain a mixed powder; S4.2: Add water to the above mixed powder, mix thoroughly, place in an extruder, perform extrusion granulation, dry at 40-60°C to constant weight, and pass through a 100-200 mesh sieve to obtain water dispersible granules.

5. The production process of thiamethoxam water dispersible granules according to claim 2, characterized in that: The mass ratios of N-hydroxysulfosuccinyl and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride to aspartic acid are 1:(1.1-1.3) and 1:(2-3), respectively.

6. The production process of thiamethoxam water dispersible granules according to claim 2, characterized in that: The molar ratio of aminated methyl methacrylate to aspartic acid is 1:(1.1-1.2).

7. The production process of thiamethoxam water dispersible granules according to claim 3, characterized in that: The volume ratio of modified methyl methacrylate to whey protein solution is 1:(5-6), and the mass ratios of N,N′-methylenebisacrylamide, potassium persulfate and 1,5-glutaraldehyde to whey protein powder are 1:(3-4), 1:(10-12) and 1:(1.3-1.5), respectively.

8. The production process of thiamethoxam water dispersible granules according to claim 4, characterized in that: Calculated by mass percentage, the water-dispersible granules include: 10-20% thiamethoxam, 3-5% dispersant, 1-3% wetting agent, 1-2% disintegrant and 0.1-0.5% binder, and the balance is eugenol-loaded powder; wherein the dispersant is one or more of sodium polycarboxylate, alkyl polyoxyethylene ether sulfonate or lignin sulfonate, the wetting agent is one or more of alkyl naphthalene sulfonate, acyl glutamate, fatty alcohol ethoxylate or fatty alcohol polyoxyethylene ether, the disintegrant is one or more of urea, sodium sulfate, calcium sulfate and sodium bicarbonate, and the binder is one or more of polyethylene glycol, carboxymethyl cellulose, polyvinyl alcohol, dextrin or xanthan gum.

9. A thiamethoxam water dispersible granule, characterized in that: The thiamethoxam water dispersible granules are prepared by the production process of the thiamethoxam water dispersible granules according to any one of claims 1 to 8.

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