A water dispersible granule of flonicamid and its preparation method and application

Abstract

The application relates to the technical field of pesticide processing, and specifically discloses an rynaxypyr water dispersible granule and a preparation method and application thereof. The rynaxypyr water dispersible granule comprises the following raw materials in parts by weight: 500-700 parts of pymetrozine wet powder, 150-250 parts of nitenpyram, 100-200 parts of SP-DF2238, 8-12 parts of SP-4026, 15-25 parts of LUX, 15-25 parts of MNS-245, 4-8 parts of a thickening agent, 1-3 parts of an antifreezing agent, 12-18 parts of a ternary copolymer and 1900-2100 parts of water; the preparation method is as follows: the raw materials except water are uniformly mixed, crushed and ground, put into water, uniformly mixed, granulated, dried and the rynaxypyr water dispersible granule is obtained. The rynaxypyr water dispersible granule has the advantages of improving the suspension rate and stability through the synergistic effect of the raw materials.

Description

Technical Field

[0001] This application relates to the field of pesticide processing technology, and in particular to a pymetrozine water-dispersible granule, its preparation method, and its application. Background Technology

[0002] Pymetrozine is a pesticide, a water-dispersible granule, with low toxicity. It is a combination of two insecticides with different mechanisms of action: pymetrozine and acetamiprid. Pymetrozine has a unique stylet-blocking effect, which quickly inhibits feeding once the pest has ingested it; acetamiprid can quickly block the transmission of nerve signals in pests. The combination of the two can effectively control rice planthoppers, and under normal application conditions, it has no adverse effects on rice growth.

[0003] Pymetrozine is a suspension concentrate containing the active ingredient and various adjuvants. The dispersion medium is water. Pymetrozine solid particles are very small and have a large surface energy. Particles dispersed in water will gradually sink due to gravity, resulting in a decrease in suspension rate. Furthermore, it is prone to decomposition due to excessively high ambient temperature, which reduces stability and leads to a decrease in efficacy. Summary of the Invention

[0004] To improve the suspension rate and stability of pymetrozine, this application provides a water-dispersible granule of pymetrozine, its preparation method, and its application.

[0005] In a first aspect, this application provides a water-dispersible granule formulation of pymetrozine, employing the following technical solution: A water-dispersible granule of pymetrozine, comprising the following raw materials in parts by weight: 500-700 parts of pymetrozine wet powder, 150-250 parts of pymetrozine, 100-200 parts of SP-DF2238, 8-12 parts of SP-4026, 15-25 parts of LUX, 15-25 parts of MNS-245, 4-8 parts of thickener, 1-3 parts of antifreeze, 12-18 parts of terpolymer, and 1900-2100 parts of water.

[0006] Preferably, the terpolymer is a copolymer of modified polyethylene glycol, 2-pentenoic acid, and isobutyl methacrylate.

[0007] By adopting the above technical solution, the pymetrozine water-dispersible granules of this application, through the synergistic effect between the raw materials, not only maintain a good suspension rate and 54℃ decomposition rate of the granules, thus improving stability, but also enhance the control efficacy of the granules against rice pests. Specifically, the 54℃ decomposition rate is 1.01-3.24%, the suspension rate is 86.66-96.56%, the control efficacy is 81.96-93.14% after 3 days of application, and the control efficacy is 84.51-98.04% after 7 days of application.

[0008] The main components are pymetrozine wet powder and acetamiprid. Pymetrozine wet powder has a unique stylet-blocking effect, which can quickly inhibit feeding in pests after they have ingested it. Acetaminophen can rapidly block the nerve transmission of pests. The combination of the two can effectively control pests. SP-DF2238, SP-4026, LUX, and MNS are auxiliary adjuvants that can improve suspension rate and wettability. Thickeners can adjust the viscosity of granules, and antifreeze agents can prevent granules from freezing at low temperatures, improving flowability and stability.

[0009] The terpolymer is a copolymer of modified polyethylene glycol ester, 2-pentenoic acid, and isobutyl methacrylate. The main chain of the terpolymer is hydrophobic, while the side chains are hydrophilic, which can play a certain stabilizing role and reduce the occurrence of random aggregation. Furthermore, the terpolymer can form carboxylate anions in water and adsorb on the surface of pymetrozine wet powder or acetamiprid in a monomolecular form, making the surface negatively charged. This attracts more ions, enhances the electrostatic repulsion between particles, improves dispersibility, and thus improves suspension rate and stability.

[0010] Preferably, the terpolymer is prepared using the following method: A1: Mix modified polyethylene glycol ester, 2-pentenoic acid, and isobutyl methacrylate evenly to obtain solution A; A2: Add the initiator to water and mix well to obtain solution B; A3: Sodium bisulfite and methanol are placed in water, mixed evenly, heated, and simultaneously added solution A and solution B dropwise. After the addition is complete, the reaction is allowed to stand, cooled, pH value is adjusted, the temperature is raised again, and methanol is distilled to obtain solution C. A4: Place solution C in carbon tetrachloride, add water, mix well, remove the organic phase, distill under reduced pressure to obtain a solid, dry it, and obtain a terpolymer.

[0011] Furthermore, the terpolymer is prepared using the following method: A1: Mix modified polyethylene glycol ester, 2-pentenoic acid, and isobutyl methacrylate evenly to obtain solution A; A2: Add the initiator to water and mix well to obtain solution B; A3: Sodium bisulfite and methanol are placed in water, mixed evenly, and heated to 70-90℃. At the same time, solutions A and B are added dropwise at a rate of 1-3 mL / min. After the addition is complete, the reaction is allowed to stand for 1-3 hours, cooled to 40-60℃, and the pH value is adjusted to 7-8 with sodium hydroxide solution. The temperature is then raised to 90-110℃ again, and the methanol is distilled to obtain solution C. A4: Place solution C in carbon tetrachloride, add water, mix well, remove the organic phase, distill under reduced pressure to obtain a solid, dry it to obtain a terpolymer; In step A2, the weight ratio of initiator to modified polyethylene glycol ester is (0.5-0.7):1, and the weight ratio of modified polyethylene glycol ester to water is 1:(3-5). In step A3, the weight ratio of modified polyethylene glycol ester to sodium bisulfite is 1:(0.7-0.9), the weight ratio of modified polyethylene glycol ester to methanol is 1:(1-2), and the weight ratio of modified polyethylene glycol ester to water is 1:(3-5). The mass fraction of sodium hydroxide solution is 40%. In step A4, the weight ratio of modified polyethylene glycol ester to carbon tetrachloride is 1:(0.6-0.7), and the weight ratio of modified polyethylene glycol ester to water is 1:(4-6).

[0012] By adopting the above technical solution and using the above preparation method to prepare terpolymers, modified polyethylene glycol ester, 2-pentenoic acid, and isobutyl methacrylate can undergo better copolymerization reaction, which facilitates the preparation of terpolymers and allows them to play a better role, further improving the suspension rate and stability of granulation agents.

[0013] Preferably, the weight ratio of the modified polyethylene glycol ester, 2-pentenoic acid, and isobutyl methacrylate is 1:(7-9):(3-5).

[0014] By adopting the above technical solution, when the addition amounts of 2-pentenoic acid and isobutyl methacrylate are within the above range, they can better undergo copolymerization reactions with modified polyethylene glycol ester, which facilitates the preparation of terpolymers, allows terpolymers to play a better role, and helps to further improve the stability of granulation agents.

[0015] Preferably, the modified polyethylene glycol ester is prepared by the following method: maleic anhydride and polyethylene glycol are mixed, a catalyst is added, and an oil bath reaction is carried out. After the reaction is completed, the modified polyethylene glycol ester is obtained.

[0016] Furthermore, the modified polyethylene glycol ester is prepared by the following method: maleic anhydride and polyethylene glycol are mixed, a catalyst is added, and an oil bath reaction is carried out at a temperature of 90-110°C for 5-7 hours. After the reaction is completed, the modified polyethylene glycol ester is obtained. The weight ratio of catalyst to polyethylene glycol is (0.4-0.6):1.

[0017] By adopting the above technical solution and preparation method, the modified polyethylene glycol ester is prepared, which facilitates the uniform mixing of raw materials and allows the modified polyethylene glycol ester to function effectively.

[0018] Preferably, the weight ratio of maleic anhydride to polyethylene glycol is (0.5-0.7):1.

[0019] By employing the above technical solution, when the amount of maleic anhydride added is low, the esterification rate is low, and the modified polyethylene glycol ester cannot be generated optimally. When the amount of maleic anhydride added is high, a certain amount of diester will be generated, resulting in a lower esterification rate for the modified polyethylene glycol ester. Therefore, when the amount of maleic anhydride added is within the above range, the esterification rate can be maximized, facilitating the generation of modified polyethylene glycol ester.

[0020] Preferably, the ternary copolymer is pretreated by the following method before use: the ternary copolymer is dissolved in carbon tetrachloride, concentrated hydrochloric acid is added dropwise, a white precipitate appears, concentrated hydrochloric acid is added dropwise until no more white precipitate appears, the precipitate is removed, washed, water is added again, centrifuged, centrifuged repeatedly, and freeze-dried to obtain the pretreated ternary copolymer.

[0021] Furthermore, the terpolymer is pretreated by the following method before use: the terpolymer is dissolved in carbon tetrachloride, concentrated hydrochloric acid is added dropwise at a rate of 1-3 mL / min, a white precipitate appears, concentrated hydrochloric acid is added dropwise until no more white precipitate appears, the precipitate is removed, washed with water 5-7 times, water is added again, centrifuged, centrifuged three times, and freeze-dried to obtain the pretreated terpolymer. The weight ratio of the terpolymer to carbon tetrachloride is 1:(0.6-0.8), the mass fraction of concentrated hydrochloric acid is 38%, and the weight ratio of the terpolymer to water is 1:(5-7).

[0022] By adopting the above technical solution and the above preparation method to pretreat the terpolymer, impurities and small molecules on the terpolymer can be removed, the purity of the terpolymer can be improved, and the terpolymer can play a better role, thereby helping to improve the suspension rate and stability of the granulation agent.

[0023] Preferably, the thickener is a mixture of magnesium aluminum silicate and xanthan gum, and the weight ratio of magnesium aluminum silicate to xanthan gum is (2-4):1.

[0024] By adopting the above technical solution, for granules, it is necessary to maintain fluidity and ensure that they do not separate or undergo Austere ripening during heat storage. Xanthan gum is an organic thickener and magnesium aluminum silicate is an inorganic thickener. When magnesium aluminum silicate or xanthan gum is used alone, the heat storage stability of the granules is not good. The heat storage stability is improved when magnesium aluminum silicate and xanthan gum are used in combination. Therefore, the two are used together as thickeners.

[0025] Secondly, this application provides a method for preparing pymetrozine water-dispersible granules, which adopts the following technical solution: A method for preparing pymetrozine water-dispersible granules includes the following steps: Pymetrozine wet powder, acetamiprid, SP-DF2238, SP-4026, LUX, MNS-245, thickener, antifreeze, and terpolymer are mixed evenly, crushed, ground, and then placed in water, mixed evenly, granulated, and dried to obtain acetamiprid water-dispersible granules.

[0026] Furthermore, a method for preparing a pymetrozine water-dispersible granule includes the following steps: Mix pymetrozine wet powder, acetamiprid, SP-DF2238, SP-4026, LUX, MNS-245, thickener, antifreeze, and terpolymer evenly, pulverize and grind to 5-10 μm, then put it into water, mix evenly, granulate, and dry to obtain acetamiprid water-dispersible granules.

[0027] By adopting the above technical solution and using the above preparation method to prepare granules, the raw materials can be mixed evenly, which facilitates the function of each raw material and helps to improve the suspension rate and stability of the granules.

[0028] Thirdly, this application provides an application of pymetrozine water-dispersible granules, employing the following technical solution: An application of a pymetrozine water-dispersible granule on rice, wherein the pymetrozine water-dispersible granule as described in any one of claims 1-8 is diluted with water to form a spray.

[0029] By adopting the above technical solution, pymetrozine water-dispersible granules can effectively control rice planthoppers and help increase rice yield.

[0030] In summary, this application includes at least one of the following beneficial technical effects: 1. Because the terpolymer made by copolymerizing modified polyethylene glycol ester, 2-pentenoic acid, and isobutyl methacrylate in this application has inherent stability and can form carboxylate anions in water, which are adsorbed in monomolecular form on the surface of pymetrozine wet powder or acetamiprid, making the surface negatively charged. This attracts more ions and enhances the electrostatic repulsion between particles, thereby improving the suspension rate and stability. The decomposition rate at 54℃ can be reduced to 1.01%, the suspension rate can reach 96.56%, the control efficacy can reach 93.14% after 3 days after application, and the control efficacy can reach 98.04% after 7 days after application.

[0031] 2. In this application, it is preferred to pretreat the terpolymer to remove impurities and small molecules from the terpolymer, eliminate the influence of other impurities, and facilitate the terpolymer to play a better role, thereby helping to improve the suspension rate and stability of the granulation agent. Detailed Implementation

[0032] The following provides a more detailed description of this application in conjunction with specific details.

[0033] raw material The antifreeze is ethylene glycol; the initiator is ammonium persulfate; the molecular weight of polyethylene glycol is 200; and the catalyst is p-toluenesulfonic acid.

[0034] Preparation Example Preparation Example 1 A modified polyethylene glycol ester, which is prepared by the following method: 1 kg of maleic anhydride and 2 kg of polyethylene glycol were mixed, and 1 kg of catalyst was added. The mixture was then reacted in an oil bath at 100°C for 6 hours. After the reaction was completed, modified polyethylene glycol ester was obtained.

[0035] Preparation Example 2 A modified polyethylene glycol ester, which differs from Preparation Example 1 in that the amount of maleic anhydride added is different; in Preparation Example 2, the amount of maleic anhydride added is 1.2 kg.

[0036] Preparation Example 3 A modified polyethylene glycol ester, which differs from Preparation Example 1 in that the amount of maleic anhydride added is different; in Preparation Example 3, the amount of maleic anhydride added is 1.4 kg.

[0037] Preparation Example 4 A terpolymer is prepared by the following method: A1: Mix 2 kg of modified polyethylene glycol ester prepared in Preparation Example 1, 14 kg of 2-glutaric acid, and 6 kg of isobutyl methacrylate evenly to obtain solution A; A 2: Add 1.2 kg of initiator to 8 kg of water and mix well to obtain solution B; A3: Add 1.6 kg of sodium bisulfite and 3 kg of methanol to 8 kg of water, mix well, heat to 80°C, and simultaneously add solution A and solution B dropwise at a rate of 2 mL / min. After the addition is complete, let the reaction stand for 2 hours, cool to 50°C, adjust the pH to 7 with a 40% sodium hydroxide solution, heat again to 100°C, and distill the methanol to obtain solution C. A4: Place solution C into 1.3 kg of carbon tetrachloride, add 10 kg of water, mix well, remove the organic phase, distill under reduced pressure to obtain a solid, dry it, and obtain a terpolymer.

[0038] Preparation Example 5 A terpolymer differs from Preparation Example 4 in that the amount of 2-pentenoic acid added in the terpolymer is different; in Preparation Example 5, the amount of 2-pentenoic acid added is 16 kg.

[0039] Preparation Example 6 A terpolymer differs from Preparation Example 4 in that the amount of 2-pentenoic acid added in the terpolymer is different; in Preparation Example 5, the amount of 2-pentenoic acid added is 18 kg.

[0040] Preparation Example 7 A terpolymer differs from Preparation Example 5 in that the amount of isobutyl methacrylate added in the terpolymer is different; in Preparation Example 7, the amount of isobutyl methacrylate added is 8 kg.

[0041] Preparation Example 8 A terpolymer differs from Preparation Example 5 in that the amount of isobutyl methacrylate added in the terpolymer is different; in Preparation Example 8, the amount of isobutyl methacrylate added is 10 kg.

[0042] Preparation Example 9 A terpolymer differs from Preparation Example 7 in that the amounts of 2-pentenoic acid and isobutyl methacrylate added in the terpolymer are different. In Preparation Example 10, the amount of 2-pentenoic acid added is 0.5 kg and the amount of isobutyl methacrylate added is 0.1 kg.

[0043] Preparation Example 10 A terpolymer differs from Preparation Example 7 in that the source of the modified polyethylene glycol ester in the terpolymer is different; the modified polyethylene glycol ester in Preparation Example 10 was prepared using Preparation Example 2.

[0044] Preparation Example 11 A terpolymer differs from Preparation Example 7 in that the source of the modified polyethylene glycol ester in the terpolymer is different; the modified polyethylene glycol ester in Preparation Example 11 was prepared using Preparation Example 3. Example

[0045] Example 1 A water-dispersible granule of pymetrozine, the raw material ratio of which is shown in Table 1.

[0046] A method for preparing pymetrozine water-dispersible granules includes the following steps: Pymetrozine wet powder, acetamiprid, SP-DF2238, SP-4026, LUX, MNS-245, thickener, antifreeze, and the terpolymer prepared according to Preparation Example 4 were mixed evenly, pulverized and ground to 7 μm, then added to water, mixed evenly, granulated, and dried to obtain acetamiprid water-dispersible granules. Examples 2-5 A water-dispersible granule of pymetrozine differs from that of Example 1 in that the raw material ratio of the granule is different, as shown in Table 1.

[0047] Table 1. Dosage of each raw material in the granular agents of Examples 1-5 (unit: kg) Examples 6-12 A water-dispersible granule of pymetrozine, which differs from Example 1 in that the terpolymer in the granule has a different source. The terpolymers in Examples 6-12 were prepared using Preparation Examples 5-11, respectively.

[0048] Example 13 A water-dispersible granule of pymetrozine, which differs from Example 11 in that the terpolymer is pretreated by the following method before use: the terpolymer is dissolved in carbon tetrachloride, concentrated hydrochloric acid is added dropwise at a rate of 2 mL / min, a white precipitate appears, concentrated hydrochloric acid is added dropwise until no more white precipitate appears, the precipitate is removed, washed with water 6 times, water is added again, centrifuged, centrifuged three times, and freeze-dried to obtain the pretreated terpolymer; The weight ratio of the terpolymer to carbon tetrachloride is 1:0.7, the mass fraction of concentrated hydrochloric acid is 38%, and the weight ratio of the terpolymer to water is 1:6.

[0049] Comparative Example Comparative Example 1 A water-dispersible granule of pymetrozine, which differs from Example 1 in that no terpolymer is added to the granule.

[0050] Comparative Example 2 A water-dispersible granule of pymetrozine, which differs from Example 1 in that 2-pentenoic acid in the terpolymer is replaced in equal amounts with isobutyl methacrylate.

[0051] Comparative Example 3 A water-dispersible granule of pymetrozine, which differs from Example 1 in that isobutyl methacrylate in the terpolymer is replaced in equal amounts with 2-pentenoic acid.

[0052] Application examples Application Example 1 An application of pymetrozine water-dispersible granules on rice, comprising 25 kg of pymetrozine water-dispersible granules prepared in Example 1 and 75 kg of water, which are then sprayed onto rice.

[0053] Application Example 2-13 The pymetrozine water-dispersible granules used in Examples 2-13 were prepared using the methods described in Examples 1-13.

[0054] Application Comparative Examples 1-3 The pymetrozine water-dispersible granules used in Comparative Examples 1-3 were prepared using Comparative Examples 1-3, respectively.

[0055] Performance testing The following performance tests were performed on Examples 1-13, Comparative Examples 1-3, Application Examples 1-13, and Application Comparative Examples 1-3: Decomposition rate: The thermal storage stability of granules was determined according to GB / T19136-2003 "Determination of Thermal Storage Stability of Pesticides". The test results are shown in Table 2.

[0056] Suspension rate: The suspension rate of granules was determined according to GB / T14825-2006 "Determination of Suspension Rate of Pesticides". The test results are shown in Table 2.

[0057] Control effect: Apply pesticide during the peak period of the third generation of young nymphs of the white-backed planthopper in rice paddies, at a rate of [percentage missing] per 667 m². 2 The pesticide was diluted with 50 kg of water for spraying. A water layer was maintained in the field during and for one week after the application. The rice variety used in this experiment was Yangfujing No. 8. The initial insect population was 510 before the application. The pesticide dosage was 100 g / mu. The residual insect population in the field was checked 3 and 7 days after the application. The insect survival rate and control effect were calculated. The test results are shown in Table 3.

[0058] Table 2 Detection Results Table 3 Detection Results As can be seen from Tables 1 and 2, the pymetrozine water-dispersible granules of this application, through the synergistic effect between the raw materials, not only maintain good suspension rate and 54℃ decomposition rate of the granules and improve stability, but also improve the control efficacy of the granules against rice pests. Specifically, the 54℃ decomposition rate is 1.01-3.24%, the suspension rate is 86.66-96.56%, the control efficacy is 81.96-93.14% 3 days after application, and the control efficacy is 84.51-98.04% 7 days after application.

[0059] Combining Example 1 and Comparative Examples 1-3, it can be seen that the granulation agent in Example 1 has a decomposition rate of 2.96% and a suspension rate of 89.97% at 54°C, which is better than that in Comparative Examples 1-3. This indicates that adding a terpolymer made of modified polyethylene glycol ester, 2-pentanoic acid, and isobutyl methacrylate to the granulation agent is more suitable and can better improve the stability and suspension rate of the granulation agent.

[0060] Combining Application Example 1 and Comparative Examples 1-3, it can be seen that the efficacy of the granular agent in Application Example 1 was 82.55% after 3 days and 85.10% after 7 days, which is better than that in Comparative Examples 1-3. This indicates that adding a terpolymer made of modified polyethylene glycol ester, 2-glutaric acid, and isobutyl methacrylate to the granular agent is more suitable and can improve the efficacy of the granular agent.

[0061] Combining Examples 1-5 and Application Examples 1-5, it can be seen that the granules in Example 4 have a decomposition rate of 2.23% and a suspension rate of 93.67% at 54°C, which are better than other examples. In Application Example 4, the efficacy of the granules after 3 days of application is 84.12%, and the efficacy after 7 days of application is 87.06%, which are better than other application examples. This indicates that the addition amount in Examples 4 and Application Example 4 is more appropriate, which can not only improve the suspension rate and stability of the granules, but also improve the efficacy.

[0062] Combining Examples 6-12 and Application Examples 6-12, it can be seen that the granules in Example 11 have a decomposition rate of 1.45% and a suspension rate of 98.42% at 54°C, which are better than other examples. In Application Example 11, the efficacy of the granules after 3 days of application is 91.76% and the efficacy after 7 days of application is 95.69%, which are better than other application examples. This indicates that the terpolymer prepared by Preparation Example 10 is more suitable, as it can not only improve the suspension rate and stability of the granules, but also improve the efficacy.

[0063] Combining Examples 11 and 13, and Application Examples 11 and 13, it can be seen that in Example 13, the granules had a decomposition rate of 1.01% and a suspension rate of 99.56% at 54°C, which is better than other examples. In Application Example 13, the efficacy of the granules was 93.14% after 3 days of application and 98.04% after 7 days of application, which is better than other application examples. This indicates that pretreatment of the terpolymer before use is more suitable, as it can better improve the suspension rate and stability of the granules and enhance the efficacy.

[0064] The embodiments described above are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A water-dispersible granule formulation of pymetrozine, characterized in that: It comprises the following raw materials in parts by weight: 500-700 parts of pymetrozine wet powder, 150-250 parts of acetamiprid, 100-200 parts of SP-DF2238, 8-12 parts of SP-4026, 15-25 parts of LUX, 15-25 parts of MNS-245, 4-8 parts of thickener, 1-3 parts of antifreeze, 12-18 parts of terpolymer, and 1900-2100 parts of water; The terpolymer is a copolymer of modified polyethylene glycol, 2-pentenoic acid, and isobutyl methacrylate, wherein the weight ratio of the modified polyethylene glycol, 2-pentenoic acid, and isobutyl methacrylate is 1:(7-9):(3-5). The modified polyethylene glycol ester is prepared by the following method: maleic anhydride and polyethylene glycol are mixed, a catalyst is added, and an oil bath reaction is carried out. After the reaction is completed, the modified polyethylene glycol ester is obtained. The terpolymer was prepared using the following method: A1: Mix modified polyethylene glycol ester, 2-pentenoic acid, and isobutyl methacrylate evenly to obtain solution A; A2: Add the initiator to water and mix well to obtain solution B; A3: Sodium bisulfite and methanol are placed in water, mixed evenly, heated, and simultaneously added solution A and solution B dropwise. After the addition is complete, the reaction is allowed to stand, cooled, pH value is adjusted, the temperature is raised again, and methanol is distilled to obtain solution C. A4: Place solution C in carbon tetrachloride, add water, mix well, remove the organic phase, distill under reduced pressure to obtain a solid, dry it, and obtain a terpolymer.

2. The pymetrozine water-dispersible granule according to claim 1, characterized in that: The weight ratio of maleic anhydride to polyethylene glycol is (0.5-0.7):

1.

3. The pymetrozine water-dispersible granule according to claim 1, characterized in that: The ternary copolymer was pretreated by the following method before use: the ternary copolymer was dissolved in carbon tetrachloride, concentrated hydrochloric acid was added dropwise, a white precipitate appeared, concentrated hydrochloric acid was added dropwise until no more white precipitate appeared, the precipitate was removed, washed, water was added again, centrifuged, centrifuged repeatedly, and freeze-dried to obtain the pretreated ternary copolymer.

4. The pymetrozine water-dispersible granule according to claim 1, characterized in that: The thickener is a mixture of magnesium aluminum silicate and xanthan gum, and the weight ratio of magnesium aluminum silicate to xanthan gum is (2-4):

1.

5. A method for preparing the pymetrozine water-dispersible granules as described in any one of claims 1-4, characterized in that, Includes the following steps: Pymetrozine wet powder, acetamiprid, SP-DF2238, SP-4026, LUX, MNS-245, thickener, antifreeze, and terpolymer are mixed evenly, crushed, ground, and then placed in water, mixed evenly, granulated, and dried to obtain acetamiprid water-dispersible granules.

6. The application of a pymetrozine water-dispersible granule on rice, characterized in that: It is prepared by diluting the pymetrozine water-dispersible granules according to any one of claims 1-5 with water to form a spray.

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