A compound insecticide for agricultural use and its preparation method

Abstract

This invention discloses an agricultural compound insecticide and its preparation method, belonging to the field of pesticide technology. The invention modifies chitosan by graft copolymerization with organosilicon monomers and acrylic monomers. The resulting modified adjuvant significantly reduces the interfacial tension between the oil and aqueous phases, exhibiting both compatibility and dispersibility, and significantly improving the stability of the emulsion system, preventing droplet aggregation, stratification, and demulsification. By combining castor oil polyoxyethylene ether with fluorinated polysiloxane as a composite emulsifier and hydroxypropyl methylcellulose as an emulsion stabilizer, a highly stable, low interfacial tension nanoemulsion system is constructed. This significantly improves the thermodynamic stability of the formulation under high and low temperature storage conditions, and gives the agricultural compound insecticide excellent dispersibility, wetting, and adhesion, improving the utilization rate and control effect of the pesticide solution, showing broad application prospects.

Description

Technical Field

[0001] This invention relates to the field of pesticide technology, and more specifically, to an agricultural compound insecticide and its preparation method. Background Technology

[0002] In agricultural production, small pests such as whiteflies, thrips, aphids, and planthoppers reproduce in large numbers and have significant generational overlap. Resistance develops extremely quickly, and the development of new pesticide varieties cannot keep up with the pace of pest resistance development. Therefore, the combination of pesticide active ingredients with different mechanisms of action has become an important means to delay pest resistance and improve control effectiveness. Biprofen, a plant-derived insecticide, features a novel structure, unique mechanism of action, and low toxicity. It is effective in controlling various small pests on crops such as rice, fruit trees, and vegetables, and shows good results in foliar, seed, and soil treatments. Pyriproxyfen, a juvenile hormone analog, has the advantages of strong systemic translocation activity, long-lasting effect, and safety for crops and the ecological environment. It has excellent control effects on various pests such as Homoptera and Thysanoptera. The combination of the two can achieve complementary mechanisms of action, further enhancing control efficacy. The combination ratio of the two has been disclosed in existing technologies, such as patent application number 20161105631.2.X, which discloses a pesticide composition containing biprofen and pyriproxyfen. However, in the development of formulations, there is still room for improvement in the stability and efficacy of the formulations.

[0003] However, existing formulations of bispyribac-pyriproxyfen and pyriproxyfen often employ conventional adjuvants, resulting in several technical drawbacks. Firstly, conventional emulsifiers are typically single-type with insufficient interfacial activity, making it difficult to effectively reduce the interfacial tension between the oil phase (active ingredient) and the aqueous phase. This leads to difficulties in mixing the oil and aqueous phases, resulting in poor emulsion stability and a tendency for droplet aggregation, stratification, and demulsification, thus affecting the storage and efficacy of the formulation. Secondly, conventional thickeners are often unmodified natural or synthetic polymers that cannot synergize with the active ingredient and emulsifier, making it difficult to construct a stable emulsion system. Furthermore, the formulations lack sufficient thermodynamic stability, making them prone to performance degradation during high and low temperature storage, further impacting efficacy.

[0004] Furthermore, with increasing environmental awareness, pesticide formulations are developing towards water-based, low-pollution, and high-stability directions. Nanoemulsions, as a novel water-based formulation, offer advantages such as small particle size, uniform dispersion, and high bioavailability. However, their preparation requires extremely high standards for interfacial tension control and droplet stability, making it difficult for existing compound formulations to simultaneously achieve a synergistic improvement in both stability and efficacy. Meanwhile, current technologies lack a technical solution for the bifenthrin / pyriproxyfen compound system that achieves low interfacial tension, stable nanoemulsions, and high thermodynamic stability through adjuvant modification and emulsifier optimization. Therefore, developing an agricultural compound insecticide based on additive innovation and its preparation method to address the shortcomings of existing technologies has significant practical importance and application value. Summary of the Invention

[0005] In view of this, in order to solve one of the above-mentioned technical problems, the present invention provides an agricultural compound insecticide and its preparation method, the specific technical solution of which is as follows: An agricultural compound insecticide, comprising the following components by weight percentage: 5%~30% insecticidal active ingredient, 0.5%~5.0% modifying adjuvant, 2.0%~8.0% compound emulsifier, 1%~5% emulsion stabilizer, 1.0%~5.0% antifreeze, 0.1%~1.0% defoamer, 0.1%~1.0% preservative, 0.5%~3% solubilizer, 0.1%~1.5% interface modifier, with the balance being deionized water; The modified additive is prepared by adding chitosan, organosilicon monomer and initiator to a reaction vessel, stirring and reacting under the first reaction condition, then adding acrylic monomer, stirring and reacting under the second reaction condition, cooling to room temperature after the reaction is completed, adding anhydrous ethanol to precipitate, and then washing, drying and pulverizing to obtain the modified additive.

[0006] Furthermore, the weight ratio of chitosan, organosilicon monomer, initiator, and acrylic monomer is (10~20):(3~8):(0.1~1):(1~5).

[0007] Furthermore, the temperature of the first reaction condition is 60~85℃, the rotation speed is 300~500r / min, and the stirring reaction time is 1~3h.

[0008] Furthermore, the temperature of the second reaction condition is 65~90℃, the rotation speed is 300~500r / min, and the stirring reaction time is 30~60min.

[0009] Furthermore, the insecticidal active ingredient is composed of bispyribac-methyl and pyriproxyfen, and the mass ratio of bispyribac-methyl to pyriproxyfen is (1~20):(1~30).

[0010] Furthermore, the composite emulsifier is obtained by compounding castor oil polyoxyethylene ether and fluorinated polysiloxane in a mass ratio of (1~5):(1~3), and the fluorine content of the fluorinated polysiloxane is 8%~15%.

[0011] Furthermore, the emulsifying stabilizer is hydroxypropyl methylcellulose.

[0012] Furthermore, the antifreeze is at least one of ethylene glycol and glycerol.

[0013] Furthermore, the preservative is at least one of Kathon and sodium benzoate.

[0014] In addition, the present invention also provides a method for preparing an agricultural compound insecticide, the preparation method comprising the following steps: S1. Mix the insecticidal active ingredient, cosolvent, and composite emulsifier, and stir to obtain the oil phase; S2. Mix deionized water, modifier, antifreeze, preservative and interface modifier, stir and treat, then add emulsifying stabilizer, continue stirring until uniform, to obtain aqueous phase; S3. Under high-speed shearing conditions, the oil phase is slowly added to the aqueous phase. After the addition is complete, shearing is performed, then defoamer is added, the shearing speed is adjusted, and stirring is continued. After homogenization, an agricultural compound insecticide is obtained.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention modifies chitosan by graft copolymerization with organosilicon monomers and acrylic monomers. The modified additive obtained can significantly reduce the interfacial tension between the oil phase and the water phase, and has both compatibility and dispersibility. It also significantly improves the stability of the emulsion system and prevents the occurrence of droplet aggregation, stratification and demulsification.

[0016] 2. This invention uses castor oil polyoxyethylene ether and fluorinated polysiloxane as a composite emulsifier, combined with hydroxypropyl methylcellulose as an emulsion stabilizer, to construct a nanoemulsion system with high stability and low interfacial tension, which significantly improves the thermodynamic stability of the formulation under high and low temperature storage conditions, thereby adapting to the storage and use requirements under different climatic conditions.

[0017] 3. By optimizing the adjuvant system, this invention can also form a protective film on the crop surface, delaying the decomposition and loss of insecticidal active ingredients. This results in the compound insecticide of bispyribac-propargyl and pyriproxyfen having excellent dispersibility, wettability and adhesion, improving the utilization rate and control effect of active ingredients. It is especially suitable for the integrated control of small pests such as whiteflies, thrips and aphids.

[0018] 4. The preparation method provided by this invention is simple and controllable, suitable for industrial production, and the resulting formulation has small particle size, uniform distribution, and good storage stability, and has broad application prospects. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to its embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the scope of protection of the invention.

[0020] An agricultural compound insecticide according to one embodiment of the present invention comprises the following components by weight percentage: 5%~30% insecticidal active ingredient, 0.5%~5.0% modifying adjuvant, 2.0%~8.0% compound emulsifier, 1%~5% emulsion stabilizer, 1.0%~5.0% antifreeze, 0.1%~1.0% defoamer, 0.1%~1.0% preservative, 0.5%~3% cosolvent, 0.1%~1.5% interface modifier, and the balance being deionized water; The modified additive is prepared by adding chitosan, organosilicon monomer and initiator to a reaction vessel, stirring and reacting under the first reaction condition, then adding acrylic monomer, stirring and reacting under the second reaction condition, cooling to room temperature after the reaction is completed, adding anhydrous ethanol to precipitate, and then washing, drying and pulverizing to obtain the modified additive.

[0021] In one embodiment, the weight ratio of chitosan, organosilicon monomer, initiator and acrylic monomer is (10~20):(3~8):(0.1~1):(1~5).

[0022] In one embodiment, the organosilicon monomer is at least one of hydrogen-containing silicone oil and trifluoropropyl methacrylate.

[0023] In one embodiment, the initiator is at least one of ammonium persulfate and azobisisobutyronitrile.

[0024] In one embodiment, the temperature of the first reaction condition is 60~85℃, the rotation speed is 300~500r / min, and the stirring reaction time is 1~3h.

[0025] In one embodiment, the temperature of the second reaction condition is 65~90°C, the rotation speed is 300~500 r / min, and the stirring reaction time is 30~60 min.

[0026] In one embodiment, the modified additive is prepared by washing 3 to 5 times with a mixture of deionized water and anhydrous ethanol (volume ratio 1:1), drying at 60 to 70°C to constant weight, pulverizing, and then passing through a 200 to 350 mesh sieve.

[0027] In one embodiment, the insecticidal active ingredient is composed of bispyribac-methyl and pyriproxyfen, and the mass ratio of bispyribac-methyl to pyriproxyfen is (1~20):(1~30).

[0028] In one embodiment, the composite emulsifier is obtained by compounding castor oil polyoxyethylene ether and fluorinated polysiloxane in a mass ratio of (1~5):(1~3), and the fluorine content of the fluorinated polysiloxane is 8%~15%.

[0029] In one embodiment, the emulsifying stabilizer is hydroxypropyl methylcellulose.

[0030] In one embodiment, the antifreeze is at least one of ethylene glycol and glycerol.

[0031] In one embodiment, the defoamer is an organosilicone defoamer.

[0032] In one embodiment, the preservative is at least one of Kathon and sodium benzoate.

[0033] In one embodiment, the cosolvent is obtained by mixing N-methylpyrrolidone and propylene glycol methyl ether in a mass ratio of 1:(1~2).

[0034] In one embodiment, the interface modifier is an alkyl glycoside, and the carbon chain length of the alkyl glycoside is C10~C14; preferably, it is an octyldecyl alkyl glycoside.

[0035] In addition, the present invention also provides a method for preparing an agricultural compound insecticide, the preparation method comprising the following steps: S1. Mix the insecticidal active ingredient, cosolvent, and composite emulsifier, and stir to obtain the oil phase; S2. Mix deionized water, modifier, antifreeze, preservative and interface modifier, stir and treat, then add emulsifying stabilizer, continue stirring until uniform, to obtain aqueous phase; S3. Under high-speed shearing conditions, the oil phase is slowly added to the aqueous phase. After the addition is complete, shearing is performed, then defoamer is added, the shearing speed is adjusted, and stirring is continued. After homogenization, an agricultural compound insecticide is obtained.

[0036] In one embodiment, in step S1, the mixture is stirred at 100 r / min to 300 r / min for 30 to 60 minutes at 50 to 70°C.

[0037] In one embodiment, in step S2, deionized water, modified additives, antifreeze, preservatives and interface modifiers are mixed and stirred at 300r / min to 500r / min at 45 to 60°C for 30 to 60 minutes. Then, an emulsifying stabilizer is added and stirring is continued for 15 to 30 minutes to obtain an aqueous phase.

[0038] In one embodiment, in step S3, under high-speed shearing conditions of 10,000 r / min to 30,000 r / min, the oil phase is slowly added to the aqueous phase at a rate of 1 to 2 mL / min. After the addition is complete, shearing continues for 20 to 40 min. Then, an antifoaming agent is added, and the shearing speed is adjusted to 500 r / min to 1,000 r / min. The mixture is stirred for 5 to 20 min and then homogenized under a pressure of 2.5 to 3.0 MPa for 3 to 5 min to obtain an agricultural compound insecticide.

[0039] The implementation schemes of the present invention will now be described in detail with reference to specific embodiments. Example 1:

[0040] In this embodiment, the agricultural compound insecticide comprises the following components by mass percentage: 19% insecticidal active ingredient, 4% modifying adjuvant, 5% compound emulsifier, 3% hydroxypropyl methylcellulose, 3% ethylene glycol, 0.5% organosilicon defoamer, 0.8% sodium benzoate, 2% solubilizer, 0.6% octyldecyl alkyl glycoside, and the balance being deionized water. This embodiment describes a method for preparing an agricultural compound insecticide, comprising the following steps: S1. Mix the insecticidal active ingredient, cosolvent and compound emulsifier, and stir at 150 r / min for 45 min at 65℃ to obtain the oil phase; The insecticidal active ingredient is composed of bispyribac-methyl and pyriproxyfen, and the mass ratio of bispyribac-methyl to pyriproxyfen is 7:12. The co-solvent is obtained by mixing N-methylpyrrolidone and propylene glycol methyl ether in a mass ratio of 1:2; The composite emulsifier is obtained by compounding castor oil polyoxyethylene ether and fluorinated polysiloxane in a mass ratio of 2:3, and the fluorine content of the fluorinated polysiloxane is 10%. S2. Deionized water, modifying agent, ethylene glycol, sodium benzoate and octyldecyl alkyl glycoside are mixed and stirred at 300 r / min at 60℃ for 45 min. Then hydroxypropyl methylcellulose is added and stirring is continued for 20 min to obtain the aqueous phase. The modified additive is prepared as follows: 12 parts by weight of chitosan, 4 parts by weight of hydrogen-containing silicone oil and 0.3 parts by weight of ammonium persulfate are added to a reaction vessel and stirred at 65°C and 350 r / min for 2 hours. Then, 2 parts by weight of acrylic monomer are added and stirred at 70°C and 350 r / min for 45 minutes. After the reaction is completed, the mixture is cooled to room temperature and washed 5 times with a mixture of deionized water and anhydrous ethanol (volume ratio 1:1). The mixture is dried at 70°C to constant weight, pulverized, and passed through a 320-mesh sieve to obtain the modified additive. S3. Under high-speed shearing conditions of 10000 r / min, the oil phase is slowly added to the aqueous phase at a rate of 1 mL / min. After the addition is complete, shearing continues for 30 min. Then, an organosilicon defoamer is added, the shearing speed is adjusted to 500 r / min, and stirring is continued for 20 min. Finally, the mixture is homogenized at a pressure of 3.0 MPa for 4 min to obtain an agricultural compound insecticide. Example 2:

[0041] In this embodiment, the agricultural compound insecticide comprises the following components by mass percentage: 20% insecticidal active ingredient, 5% modifying adjuvant, 4% compound emulsifier, 4% hydroxypropyl methylcellulose, 3% ethylene glycol, 0.5% organosilicon defoamer, 0.8% sodium benzoate, 2% solubilizer, 0.5% octyldecyl alkyl glycoside, and the balance being deionized water. This embodiment describes a method for preparing an agricultural compound insecticide, comprising the following steps: S1. Mix the insecticidal active ingredient, cosolvent and compound emulsifier, and stir at 150 r / min for 45 min at 70℃ to obtain the oil phase; The insecticidal active ingredient is composed of bispyribac-methyl and pyriproxyfen, and the mass ratio of bispyribac-methyl to pyriproxyfen is 8:12. The co-solvent is obtained by mixing N-methylpyrrolidone and propylene glycol methyl ether in a mass ratio of 1:2; The composite emulsifier is obtained by compounding castor oil polyoxyethylene ether and fluorinated polysiloxane in a mass ratio of 2:3, and the fluorine content of the fluorinated polysiloxane is 10%. S2. Deionized water, modifying agent, ethylene glycol, sodium benzoate and octyldecyl alkyl glycoside are mixed and stirred at 300 r / min at 60℃ for 45 min. Then hydroxypropyl methylcellulose is added and stirring is continued for 25 min to obtain the aqueous phase. The modified additive is prepared as follows: 15 parts by weight of chitosan, 5 parts by weight of hydrogen-containing silicone oil and 0.4 parts by weight of ammonium persulfate are added to a reaction vessel and stirred at 65°C and 300 r / min for 2 hours. Then, 2 parts by weight of acrylic monomer are added and stirred at 75°C and 300 r / min for 50 minutes. After the reaction is completed, the mixture is cooled to room temperature and washed 5 times with a mixture of deionized water and anhydrous ethanol (volume ratio 1:1). The mixture is dried at 70°C to constant weight, pulverized, and passed through a 320-mesh sieve to obtain the modified additive. S3. Under high-speed shearing conditions of 10000 r / min, the oil phase is slowly added to the aqueous phase at a rate of 1 mL / min. After the addition is complete, shearing continues for 30 min. Then, an organosilicon defoamer is added, the shearing speed is adjusted to 500 r / min, and stirring is continued for 20 min. Finally, the mixture is homogenized at a pressure of 3.0 MPa for 5 min to obtain an agricultural compound insecticide. Example 3:

[0042] In this embodiment, the agricultural compound insecticide comprises the following components by mass percentage: 20% insecticidal active ingredient, 5% modifying adjuvant, 5% compound emulsifier, 5% hydroxypropyl methylcellulose, 4% ethylene glycol, 0.6% organosilicon defoamer, 0.8% sodium benzoate, 3% solubilizer, 0.8% octyldecyl alkyl glycoside, and the remainder being deionized water. This embodiment describes a method for preparing an agricultural compound insecticide, comprising the following steps: S1. Mix the insecticidal active ingredient, cosolvent and compound emulsifier, and stir at 150 r / min for 60 min at 70℃ to obtain the oil phase; The insecticidal active ingredient is composed of bispyribac-methyl and pyriproxyfen, and the mass ratio of bispyribac-methyl to pyriproxyfen is 9:11. The co-solvent is obtained by mixing N-methylpyrrolidone and propylene glycol methyl ether in a mass ratio of 1:2; The composite emulsifier is obtained by compounding castor oil polyoxyethylene ether and fluorinated polysiloxane in a mass ratio of 2:3, and the fluorine content of the fluorinated polysiloxane is 8%~15%. S2. Deionized water, modifying agent, ethylene glycol, sodium benzoate and octyldecyl alkyl glycoside are mixed and stirred at 300 r / min at 60℃ for 50 min. Then hydroxypropyl methylcellulose is added and stirring is continued for 25 min to obtain the aqueous phase. The modified additive is prepared as follows: 15 parts by weight of chitosan, 6 parts by weight of hydrogen-containing silicone oil and 0.5 parts by weight of ammonium persulfate are added to a reaction vessel and stirred at 65°C and 300 r / min for 2 hours. Then, 2 parts by weight of acrylic monomer are added and stirred at 75°C and 300 r / min for 50 minutes. After the reaction is completed, the mixture is cooled to room temperature and washed 5 times with a mixture of deionized water and anhydrous ethanol (volume ratio 1:1). The mixture is dried at 70°C to constant weight, pulverized, and passed through a 320-mesh sieve to obtain the modified additive. S3. Under high-speed shearing conditions of 10000 r / min, the oil phase is slowly added to the aqueous phase at a rate of 1 mL / min. After the addition is complete, shearing continues for 35 min. Then, an organosilicon defoamer is added, the shearing speed is adjusted to 500 r / min, and stirring is continued for 20 min. Finally, the mixture is homogenized at a pressure of 3.0 MPa for 5 min to obtain an agricultural compound insecticide.

[0043] Comparative Example 1: The difference between Comparative Example 1 and Example 3 is that no modifying agent was added in Comparative Example 1, but otherwise it is the same as Example 3.

[0044] Comparative Example 2: The difference between Comparative Example 2 and Example 3 is that chitosan was used instead of the modified assistant in Comparative Example 2, while the rest was the same as in Example 3.

[0045] Comparative Example 3: The difference between Comparative Example 3 and Example 3 is that only castor oil polyoxyethylene ether was used as an emulsifier in Comparative Example 3, while the rest was the same as in Example 3.

[0046] Comparative Example 4: The difference between Comparative Example 4 and Example 3 is that hydroxypropyl methylcellulose (emulsion stabilizer) was not added in Comparative Example 4, but otherwise it was the same as Example 3.

[0047] The agricultural compound insecticide samples prepared in Examples 1-3 and the agricultural compound insecticide samples prepared in Comparative Examples 1-4 were tested. The results are shown in Tables 1-2.

[0048] The average particle size and particle size distribution were determined using dynamic light scattering. Samples were taken, diluted with deionized water to an appropriate concentration (usually 1:100), placed in a sample cell, and the average particle size (Z-average) and polydispersity index (PDI) were measured at 25°C. Each sample was measured three times, and the average value was taken.

[0049] Surface tension: Dilute the sample with deionized water to a concentration of 1% (based on active ingredient), and measure the surface tension at 25±0.5℃. Each sample is measured three times, and the average value is taken.

[0050] Stability at room temperature: Place the sample in a sealed glass bottle and store it at 25±2℃ for 30 days. On the 30th day, observe the appearance, layering, and precipitation of the sample.

[0051] Thermal storage stability: The sample was placed in a sealed glass bottle and stored in a constant temperature chamber at 54±2℃ for 14 days. After being taken out, it was restored to room temperature. The appearance, layering, and precipitation were observed, and the particle size change was measured. The particle size change rate was calculated (change rate % = [D14-D0] / D0×100%).

[0052] Cold storage stability: Take a sample and place it in a sealed glass bottle. Store it at 0±2℃ for 7 days. After taking it out, restore it to room temperature and observe whether there is layering or precipitation. Measure the change in particle size to determine its reversibility.

[0053] Efficacy test: Indoor bioassay method; Test pest: aphids (e.g., melon aphid); Take samples and dilute with deionized water to an appropriate concentration (usually 1:100); Treat the test aphids by spraying, repeating each treatment 3 times, with no less than 30 aphids per repeat; After treatment, place the aphids in a rearing room at 25±1℃, relative humidity 60%~70%, and light cycle 16:8 h; Check the number of dead aphids 72 hours after treatment (aphids that do not move when lightly touched with a brush are considered dead), and calculate the mortality rate: Mortality rate = (number of dead insects / total number of insects treated) × 100%; if the mortality rate of the control group is >10%, it needs to be corrected using the Abbott formula.

[0054] Table 1: Test Results 1 Group Average particle size (nm) Particle size distribution (PDI) Surface tension (mN / m) Example 1 126.8 0.14 28.1 Example 2 126.1 0.12 27.6 Example 3 125.7 0.10 27.4 Comparative Example 1 356.2 0.41 43.2 Comparative Example 2 292.5 0.35 39.1 Comparative Example 3 320.4 0.33 41.5 Comparative Example 4 279.8 0.31 37.7 Table 2: Test Results 2 Group Stability at room temperature (30 days) Thermal storage stability (54℃, 14d) Cold storage stability (0℃, 7d) Efficacy test (72h, aphid mortality rate %) Example 1 No layering, no sedimentation No stratification, particle size change rate 4.2% No delamination, well restored 96.1 Example 2 No layering, no sedimentation No stratification, particle size change rate 3.8% No delamination, well restored 96.8 Example 3 No layering, no sedimentation No stratification, particle size variation rate 3.7% No delamination, well restored 97.4 Comparative Example 1 Clear stratification and sedimentation Severe stratification, demulsification Layering, irreversible 77.9 Comparative Example 2 Slight stratification Stratification, particle size change rate 22.6% Layering, irreversible 82.9 Comparative Example 3 Layering, sedimentation Stratification, particle size change rate 20.7% Slight stratification 76.6 Comparative Example 4 Slight stratification Stratification, particle size change rate 12.6% Slight stratification 87.9 Analysis of the data in Tables 1 and 2 shows that the agricultural compound insecticide prepared by this invention has a narrow particle size distribution and good emulsion uniformity. In contrast, Comparative Examples 1-4 all exhibited varying degrees of stratification, precipitation, or droplet aggregation. This indicates that the present invention, through the synergistic effect of modified adjuvants and composite emulsifiers, can effectively reduce interfacial tension and promote the formation and stabilization of nano-sized droplets. Reduced surface tension facilitates the wetting and spreading of the pesticide on the crop surface, improving pesticide utilization. Comparative Example 1 (without modified adjuvants) showed the highest surface tension, indicating that the modified adjuvants play a key role in reducing interfacial tension. Examples 1-3 showed no stratification or precipitation, demonstrating excellent performance; Comparative Examples 1-4 all showed stratification or precipitation, indicating that the formulation of this invention has good stability at room temperature. Examples 1-3 had a particle size change rate ≤4.2% and no obvious stratification; Comparative Examples 1-4 had a particle size change rate ≥12.6% and showed stratification and demulsification, indicating that the formulation of this invention has excellent thermodynamic stability and is suitable for storage in high-temperature environments. Examples 1-3 showed no stratification after recovery, indicating reversible particle size distribution; Comparative Examples 1-4 showed irreversible stratification or precipitation, demonstrating the good low-temperature stability of the present invention and its adaptability to different climatic conditions. The efficacy against aphids in the examples was significantly greater than in the comparative examples, indicating that the formulation of the present invention has small particle size, uniform dispersion, and low surface tension, enabling the formation of a uniform drug film on the target surface and improving the bioavailability and persistence of the active ingredient. Overall, the present invention, through the synergistic optimization of modified adjuvants, compound emulsifiers, and emulsion stabilizers, significantly improves the particle size uniformity, interfacial activity, storage stability, and bioactivity of agricultural compound insecticides. Compared with control formulations without modified adjuvants, single emulsifiers, or without added emulsion stabilizers, the overall performance advantages are significant, demonstrating practical application value.

[0055] To further verify the efficacy, field control effect tests were conducted, with identical application time and dosage for each group. Each treatment had three replicate plots, each 30 m², arranged in a randomized block design. The active ingredient was diluted to an effective concentration of 100 mg / L, and sprayed evenly using an electric sprayer at a rate of 45 L / mu.

[0056] Insect population reduction rate in the treated area = (Number of insects before application - Number of insects after application) / Number of insects before application × 100%; Field control effect (%) = (Pest population reduction rate in the pesticide application area - Pest population reduction rate in the blank control area) / (100% - Pest population reduction rate in the blank control area) × 100%.

[0057] Table 3: Field efficacy tests Group 1 day after medication / % 7 days after medication / % 14 days after medication / % Example 1 68.5 92.3 87.5 Example 2 70.2 92.9 88.3 Example 3 71.3 93.2 89.7 Comparative Example 1 52.3 70.2 64.8 Comparative Example 2 55.7 76.5 68.7 Comparative Example 3 53.6 73.4 65.6 Comparative Example 4 58.9 79.8 73.8 Analysis of the data in Table 3 shows that, 1 day after application, the pesticide in the examples exhibited a high control effect, indicating that the formulation of the present invention, due to its small particle size and low surface tension, can quickly wet and spread on the target surface, allowing the active ingredients to rapidly enter the pest's body, demonstrating good rapid efficacy. 7 days after application, excellent control effects were achieved, while the control effect of the samples in the comparative examples was significantly worse than that of the examples. This indicates that, under the synergistic effect of the adjuvant system (modified adjuvant + compound emulsifier + emulsion stabilizer), the formulation of the present invention can form a stable pesticide film on the crop surface, delaying the decomposition and loss of active ingredients, thereby prolonging the residual effect. 14 days after application, the examples still showed a high control effect with a small decrease; while the comparative group showed a significant decrease, further demonstrating that the formulation of the present invention has good residual efficacy under field conditions, reducing the number of applications and lowering pesticide costs. Overall, the agricultural compound insecticide described in this invention exhibits excellent rapid-acting, sustained-acting, and residual effects against melon aphids under field conditions, significantly superior to the comparative examples. This further demonstrates that the present invention achieves a balance between formulation stability and biological activity through the synergistic optimization of modified adjuvants, compound emulsifiers, and emulsion stabilizers, and has significant value for promotion and application.

[0058] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0059] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. An agricultural compound insecticide, characterized in that, The agricultural compound insecticide comprises the following components by weight percentage: 5%~30% insecticidal active ingredient, 0.5%~5.0% modifying adjuvant, 2.0%~8.0% compound emulsifier, 1%~5% emulsion stabilizer, 1.0%~5.0% antifreeze, 0.1%~1.0% defoamer, 0.1%~1.0% preservative, 0.5%~3% solubilizer, 0.1%~1.5% interface modifier, and the balance being deionized water; The modified additive is prepared by adding chitosan, organosilicon monomer and initiator to a reaction vessel, stirring and reacting under the first reaction condition, then adding acrylic monomer, stirring and reacting under the second reaction condition, cooling to room temperature after the reaction is completed, adding anhydrous ethanol to precipitate, and then washing, drying and pulverizing to obtain the modified additive.

2. The agricultural compound insecticide according to claim 1, characterized in that, The weight ratio of chitosan, organosilicon monomer, initiator and acrylic monomer is (10~20):(3~8):(0.1~1):(1~5).

3. The agricultural compound insecticide according to claim 1, characterized in that, The first reaction conditions are a temperature of 60~85℃, a rotation speed of 300~500r / min, and a stirring reaction time of 1~3h.

4. The agricultural compound insecticide according to claim 1, characterized in that, The second reaction condition is a temperature of 65~90℃, a rotation speed of 300~500r / min, and a stirring reaction time of 30~60min.

5. The agricultural compound insecticide according to claim 1, characterized in that, The insecticidal active ingredient is composed of bispyribac-methyl and pyriproxyfen, and the mass ratio of bispyribac-methyl to pyriproxyfen is (1~20):(1~30).

6. The agricultural compound insecticide according to claim 1, characterized in that, The composite emulsifier is obtained by compounding castor oil polyoxyethylene ether and fluorinated polysiloxane in a mass ratio of (1~5):(1~3), and the fluorine content of the fluorinated polysiloxane is 8%~15%.

7. The agricultural compound insecticide according to claim 1, characterized in that, The emulsifying stabilizer is hydroxypropyl methylcellulose.

8. The agricultural compound insecticide according to claim 1, characterized in that, The antifreeze is at least one of ethylene glycol and glycerol.

9. The agricultural compound insecticide according to claim 1, characterized in that, The preservative is at least one of Kathon and sodium benzoate.

10. A method for preparing an agricultural compound insecticide, characterized in that, The preparation method is used to prepare the agricultural compound insecticide according to any one of claims 1 to 9, and the preparation method includes the following steps: S1. Mix the insecticidal active ingredient, cosolvent, and composite emulsifier, and stir to obtain the oil phase; S2. Mix deionized water, modifier, antifreeze, preservative and interface modifier, stir and treat, then add emulsifying stabilizer, continue stirring until uniform, to obtain aqueous phase; S3. Under high-speed shearing conditions, the oil phase is slowly added to the aqueous phase. After the addition is complete, shearing is performed, then defoamer is added, the shearing speed is adjusted, and stirring is continued. After homogenization, an agricultural compound insecticide is obtained.