Agricultural complex insecticide and preparation method thereof

Abstract

This invention discloses an agricultural compound insecticide and its preparation method, belonging to the field of pesticide production technology. Firstly, the compound insecticide comprises the following raw materials by mass percentage: 1.8%–2.5% benzyl chlorpyrifos, 5.0%–6.5% flonicamid, and PVP / VAc-g-C. 18 The copolymer comprises 2.2%–3.0%, sodium lauroyl sarcosinate 2.0%–3.0%, xanthan gum 0.18%–0.22%, glycerol 6.0%–8.0%, and the balance being deionized water. This invention utilizes molecular design (PVP / VAc-g-C...) 18 The coupling of copolymers and process innovation (step cooling) has for the first time overcome the two major technical bottlenecks of low-temperature precipitation and low permeability in compound insecticides, providing a new solution for agricultural production.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of pesticide production, and particularly relates to an agricultural compound insecticide and a preparation method thereof. BACKGROUND

[0002] In the prevention and control of crop pests, Lepidoptera (such as cotton bollworm) and Homoptera (such as aphids) pests often occur mixedly, and a single pesticide is difficult to simultaneously prevent and control. A compound insecticide can expand the insecticidal spectrum and reduce the risk of resistance by ingredient synergy, and has become a core means of modern agricultural pest integrated control and is widely used in economic crops such as cotton and vegetables.

[0003] The current mainstream compound (such as pyrethroid + nicotine) has the defect of low-temperature storage stability: when the environmental temperature is lower than 10℃, the effective components are easy to crystallize and precipitate, resulting in spray blockage and uneven distribution of pesticide solution. In addition to the problem of low-temperature precipitation, the existing compound also has the defect of poor leaf penetration: pyrethroids have low polarity and are difficult to penetrate the wax layer; nicotine has internal penetration, but has a low retention rate on thick-wax crop leaves such as cabbage and flowers, resulting in low actual utilization rate.

[0004] In northern China, the high-incidence period of crop pests in early spring / late autumn often encounters low-temperature weather (5-15℃), and the precipitation of the pesticide directly leads to failure of prevention and control. At the same time, uneven distribution of the pesticide solution caused by low-temperature precipitation and poor leaf penetration result in an effective utilization rate of less than 30% of the pesticide. The current technology cannot simultaneously solve the two coupled problems: increasing the penetration agent will exacerbate the low-temperature precipitation (such as the increase in precipitation rate caused by the organic silicon additive), forming a technical dead cycle. SUMMARY

[0005] The purpose of the present application is to develop a compound insecticide with low-temperature stability and leaf penetration, and for this purpose, the present application provides an agricultural compound insecticide and a preparation method thereof.

[0006] Specifically, the purpose of the present application can be achieved by the following technical solutions:

[0007] An agricultural compound insecticide comprises the following raw materials in mass percentage:

[0008] Bifenthrin 1.8% to 2.5%;

[0009] Flonicamid 5.0% to 6.5%;

[0010] PVP / VAc-g-C 18 Copolymer 2.2% to 3.0%;

[0011] Sodium lauroyl sarcosinate 2.0% to 3.0%;

[0012] Xanthan gum 0.18% to 0.22%;

[0013] Glycerol 6.0%–8.0%;

[0014] The remainder is deionized water.

[0015] Furthermore, the agricultural compound insecticide comprises the following raw materials by weight percentage:

[0016] Benzyl chlorpyrifos 2.2%;

[0017] Flupyradifurone 6.0%;

[0018] PVP / VAc-gC 18 Copolymer 2.8%;

[0019] Sodium lauroyl sarcosinate 2.5%;

[0020] Xanthan gum 0.20%;

[0021] Glycerol 7.0%;

[0022] The remainder is deionized water.

[0023] Furthermore, the PVP / VAc-gC 18 The copolymer is prepared by the following steps:

[0024] N-vinylpyrrolidone, vinyl acetate, octadecyl methacrylate, and azobisisobutyronitrile were added to anhydrous ethanol. After addition, nitrogen gas was introduced into the system, maintaining a nitrogen protection flow rate of 0.2 L / min. Gradient temperature polymerization was then carried out. After completion, the reaction solution was quickly poured into n-hexane at -20℃ and allowed to stand for 2–4 h. The precipitate was then filtered and subjected to supercritical CO2 extraction. After extraction, the product was vacuum dried for 12 h to obtain PVP / VAc-gC. 18 Copolymer.

[0025] In the above preparation process, PVP (hydrophilic units) and VAc (flexible segments) constitute the polymer backbone, and the grafted C 18 Long chains (SMA derivative) form hydrophobic cavities, which can inhibit crystallization. Meanwhile, C... 18 The chain has a waxy anchoring effect, which can enhance leaf surface penetration; specifically, C 18 Chains (length ≈ 2.4 nm) and plant wax layers (C 20 -C 40 Similar in structure to alkanes, they are "pinned" into the waxy gaps by hydrophobic forces to achieve an anchoring effect.

[0026] Further, the amount ratio of the anhydrous ethanol, N-vinylpyrrolidone, vinyl acetate, octadecyl methacrylate, and azobis isobutyronitrile is 500 mL:45 g:30 g:18-22 g:0.8-1.0 g.

[0027] Further, the gradient temperature polymerization is: first heated to 40-50℃, constant temperature stirring for 20-30 min, then heated to 62-65℃, constant temperature stirring for 3 h, and then heated to 72℃, constant temperature stirring for 1-2 h.

[0028] Further, the supercritical CO2 extraction is: the extraction pressure is set to 30-35 MPa, the temperature is set to 45-50℃, the CO2 flow rate is set to 10-12 kg / h, and the extraction time is 120 min.

[0029] Further, the preparation method of the agricultural compound insecticide comprises the following steps:

[0030] According to the mass percentage, each raw material is weighed, 70% of the total amount of glycerol and PVP / VAc-g-C 18 copolymer are added in a reaction kettle, the system is heated to 45-48℃, low-speed stirring is performed at 300 rpm for 1-2 h, then benzyl chrysanthemum and flonicamid are added, after the addition is completed, the system is heated to 55-57℃, then sodium lauroyl sarcosinate is added, after the addition is completed, stirring is performed at 800 rpm for 10 min, then the speed is reduced to 500 rpm for stirring for 20 min, then the temperature is reduced to 40℃ at a reduction rate of 1℃ / min, then xanthan gum and the remaining 30% of glycerol are added, and stirring is performed at 400 rpm for 15-20 min to obtain a mixture, then the mixture is transferred to an emulsifying tank, deionized water preheated to 40℃ is added to the emulsifying tank, then a stepwise temperature reduction emulsification process is performed, after the process is completed, the mixture is filtered through a 200-mesh screen to obtain the agricultural compound insecticide.

[0031] In the above raw materials, the sodium lauroyl sarcosinate has the functions of reducing surface tension, assisting spreading, and synergizing with the charge of the PVP / VAc-g-C 18 copolymer, specifically, the zwitterionic property of the sodium lauroyl sarcosinate enables it to be oriented and arranged at the oil / water interface, at the same time, the carboxyl group (-COO - ) of the sodium lauroyl sarcosinate forms an ion-dipole interaction with the pyrrolidone group (dipole moment 4.1D) of the PVP, thereby strengthening the stability of the agricultural compound insecticide; the glycerol can wrap the pesticide molecules through a hydrogen bond network (-OH interacts with the ether bond of benzyl chrysanthemum), thereby reducing the freezing point and inhibiting precipitation; the xanthan gum forms a viscoelastic film on the leaf surface through the shear-thinning fluid property, thereby delaying the loss of the pesticide solution (retention rate is improved).

[0032] Further, the stepwise cooling emulsification process: from 40℃ to 30℃ at a cooling rate of 2℃ / min, then to 25℃ at a cooling rate of 1℃ / min, and then to 5℃ at a cooling rate of 0.5℃ / min.

[0033] Advantages of the present application:

[0034] (1) Breakthrough in low-temperature stability: By optimizing the dosage of octadecyl methacrylate (18-22 g, preferably 20 g) and using the stepwise cooling process, the present application reduces the precipitation rate of the agricultural complex insecticide from the industry's conventional >5% (Comparative Examples 5 / 7 / 9) to <0.3% (Example 5), solving the problem of low-temperature application in northern China.

[0035] (2) Breaking the technical dead loop of permeability: The C 18 hydrophobic chain in the PVP / VAc-g-C 18 copolymer prepared by the present application cooperates with the amphoteric surfactant to reduce the precipitation rate of the agricultural complex insecticide while increasing the retention rate from 40%-50% (Comparative Examples 6 / 7) to 86%, breaking the industry's paradox of "increasing permeability and intensifying precipitation".

[0036] (3) Overall improvement in insecticidal efficacy: Based on the above synergistic effect, after spraying the agricultural complex insecticide prepared by the present application, the mortality rate of cotton bollworms / aphids is increased to 95% / 93% (Example 5), far exceeding the optimal value of the comparative examples (88% / 85%), achieving "one dose, double protection" for efficient management.

[0037] In summary, by coupling molecular design (PVP / VAc-g-C 18 copolymer) with process innovation (stepwise cooling), the present application has for the first time simultaneously solved the two technical bottlenecks of low-temperature precipitation and low permeability in complex insecticides, providing a new solution for agricultural production. DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments of the present application will be described below in conjunction with the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of the present application. Meanwhile, the raw materials, reagents or devices used in the following embodiments, if not specifically stated, can be obtained from conventional commercial channels or can be obtained by existing known methods.

[0039] Example 1:

[0040] Preparation of PVP / VAc-g-C 18 copolymer:

[0041] Into a 1L four-necked flask, 500 mL of absolute ethanol, 45 g of N-vinylpyrrolidone (NVP), 30 g of vinyl acetate (VAc), 18 g of stearyl methacrylate (SMA) and 0.8 g of azobisisobutyronitrile (AIBN) were added. After the addition, a condenser, a stirring rod, a thermometer and a nitrogen inlet tube were installed, and the nitrogen protection flow rate was maintained at 0.2 L / min. Then, gradient temperature polymerization was performed. Specifically, the temperature was first raised to 40°C, and the reaction was stirred at this temperature for 20 min. Then, the temperature was raised to 62°C, and the reaction was stirred at this temperature for 3 h. Then, the temperature was raised to 72°C, and the reaction was stirred at this temperature for 1 h. After the reaction was completed, the reaction solution was quickly poured into n-hexane at -20°C, and the mixture was allowed to stand for 2 h. Then, the white flocculent precipitate was filtered. The precipitate was then subjected to supercritical CO2 extraction. The extraction pressure was set to 30 MPa, the temperature was set to 45°C, the CO2 flow rate was set to 10 kg / h, and the extraction time was set to 120 min (fractional elution: VAc was collected in the first 60 min, and SMA was collected in the last 60 min). After the extraction was completed, the obtained product was placed in a vacuum drying oven at 55°C and -0.095 MPa for 12 h. After the vacuum drying was completed, PVP / VAc-g-C 18 copolymer was obtained.

[0042] Example 2

[0043] Preparation of PVP / VAc-g-C 18 copolymer:

[0044] Into a 1L four-necked flask, 500 mL of absolute ethanol, 45 g of N-vinylpyrrolidone (NVP), 30 g of vinyl acetate (VAc), 18 g of stearyl methacrylate (SMA) and 0.8 g of azobisisobutyronitrile (AIBN) were added. After the addition, a condenser, a stirring rod, a thermometer and a nitrogen inlet tube were installed, and the nitrogen protection flow rate was maintained at 0.2 L / min. Then, gradient temperature polymerization was performed. Specifically, the temperature was first raised to 40°C, and the reaction was stirred at this temperature for 20 min. Then, the temperature was raised to 62°C, and the reaction was stirred at this temperature for 3 h. Then, the temperature was raised to 72°C, and the reaction was stirred at this temperature for 1 h. After the reaction was completed, the reaction solution was quickly poured into n-hexane at -20°C, and the mixture was allowed to stand for 2 h. Then, the white flocculent precipitate was filtered. The precipitate was then subjected to supercritical CO2 extraction. The extraction pressure was set to 30 MPa, the temperature was set to 45°C, the CO2 flow rate was set to 10 kg / h, and the extraction time was set to 120 min (fractional elution: VAc was collected in the first 60 min, and SMA was collected in the last 60 min). After the extraction was completed, the obtained product was placed in a vacuum drying oven at 55°C and -0.095 MPa for 12 h. After the vacuum drying was completed, PVP / VAc-g-C 18 copolymer was obtained.

[0045] Example 3

[0046] PVP / VAc-g-C 18 copolymer:

[0047] Into a 1L four-necked flask, 500mL of anhydrous ethanol, 45g of N-vinylpyrrolidone (NVP), 30g of vinyl acetate (VAc), 22g of stearyl methacrylate (SMA) and 1.0g of azobisisobutyronitrile (AIBN) were added, after the addition was completed, a condenser, a stirring rod, a thermometer and a nitrogen inlet tube were installed, the nitrogen protection flow rate was maintained at 0.2L / min, and gradient temperature polymerization was carried out, specifically, first heated to 50℃, constant temperature stirring reaction for 30min, then heated to 65℃, constant temperature stirring reaction for 3h, then heated to 72℃, constant temperature stirring reaction for 2h, after completion, the reaction liquid was quickly poured into -20℃ n-hexane, and stood for 4h, then filtered to obtain white flocculent precipitate, and the precipitate was subjected to supercritical CO2 extraction, the specific parameters were: the extraction pressure was set to 35MPa, the temperature was set to 50℃, the CO2 flow rate was set to 12kg / h, and the extraction time was 120min (fractional elution: VAc was collected for the first 60min, and SMA was collected for the last 60min), after the extraction was completed, the obtained product was placed in a vacuum drying oven at 60℃ and -0.095MPa for 12h, after completion, PVP / VAc-g-C 18 copolymer.

[0048] Comparative Example 1:

[0049] Comparative Example 1 is a control group of Example 2, the amount of stearyl methacrylate (SMA) in Example 2 is adjusted to 15g, and the rest of the raw materials, the amount of raw materials and the preparation steps remain consistent with Example 2, finally PVP / VAc-g-C 18 copolymer.

[0050] Comparative Example 2:

[0051] Comparative Example 2 is a control group of Example 2, the amount of stearyl methacrylate (SMA) in Example 2 is adjusted to 25g, and the rest of the raw materials, the amount of raw materials and the preparation steps remain consistent with Example 2, finally PVP / VAc-g-C 18 copolymer.

[0052] Comparative Example 3:

[0053] Comparative Example 3 is a control group of Example 2, the stearyl methacrylate (SMA) in Example 2 is removed, and the rest of the raw materials, the amount of raw materials and the preparation steps remain consistent with Example 2, finally PVP / VAc copolymer is obtained.

[0054] Example 4:

[0055] Preparation of an agricultural complex insecticide:

[0056] First, the preparation method of the agricultural compound insecticide, comprising the following steps:

[0057] Bifenthrin 2.2%;

[0058] Flonicamid 6.0%;

[0059] The PVP / VAc-g-C 18 copolymer prepared in Example 1 is 2.2%;

[0060] Sodium lauroyl sarcosinate 2.0%;

[0061] Xanthan gum 0.18%;

[0062] Glycerol 6.0%;

[0063] The balance is deionized water.

[0064] Then, the preparation method of the agricultural compound insecticide, comprising the following steps:

[0065] According to the mass percentage, each raw material is weighed, 70% of the total amount of glycerol (medical grade) and the PVP / VAc-g-C 18 copolymer prepared in Example 1 is added to the reaction kettle, the system is heated to 45°C, and low-speed stirring is carried out at 300 rpm for 1 h, then bifenthrin (technical ≥96%) and flonicamid (technical ≥97%) are added, after the addition is completed, the system is heated to 55°C, then sodium lauroyl sarcosinate (purity ≥97.0%) is added, after the addition is completed, stirring is carried out at 800 rpm for 10 min, then the speed is reduced to 500 rpm for stirring for 20 min, then the temperature is reduced to 40°C at a rate of 1°C / min, then xanthan gum (food grade) and the remaining 30% glycerol are added, stirring is carried out at 400 rpm for 15 min, to obtain a mixture, then the mixture is transferred to an emulsifying tank, deionized water preheated to 40°C is added to the emulsifying tank, then a stepwise cooling emulsification process is carried out: the temperature is reduced from 40°C to 30°C at a rate of 2°C / min, then the temperature is reduced to 25°C at a rate of 1°C / min, then the temperature is reduced to 5°C at a rate of 0.5°C / min, after completion, impurities are removed through a 200 mesh screen, etc., to obtain the agricultural compound insecticide.

[0066] Example 5:

[0067] Preparation of the agricultural compound insecticide:

[0068] First, the preparation method of the agricultural compound insecticide, comprising the following steps:

[0069] Bifenthrin 2.2%;

[0070] Flonicamid 6.0%;

[0071] PVP / VAc-g-C prepared in Example 2 18 copolymer 2.8%;

[0072] sodium lauroyl sarcosinate 2.5%;

[0073] xanthan gum 0.20%;

[0074] glycerol 7.0%;

[0075] the balance being deionized water.

[0076] Then, the preparation method of the agricultural complex insecticide comprises the following steps:

[0077] According to the mass percentage, each raw material is weighed, 70% of the total amount of glycerol (medical grade) and PVP / VAc-g-C prepared in Example 2 18 copolymer is added, the system is heated to 47°C, and low-speed stirring is carried out at 300 rpm for 2h, then benzyl chlorpyrifos (≥96% technical material) and flonicamid (≥97% technical material) are added, after the addition is completed, the system is heated to 55°C, then sodium lauroyl sarcosinate (purity ≥97.0%) is added, after the addition is completed, stirring is carried out at 800 rpm for 10 min, then the speed is reduced to 500 rpm for stirring for 20 min, then the temperature is reduced to 40°C at a rate of 1°C / min, then xanthan gum (food grade) and the remaining 30% glycerol are added, and stirring is carried out at 400 rpm for 20 min to obtain a mixture, then the mixture is transferred to an emulsifying tank, deionized water preheated to 40°C is added to the emulsifying tank, and then a stepwise cooling emulsification process is carried out: the temperature is reduced from 40°C to 30°C at a rate of 2°C / min, then the temperature is reduced to 25°C at a rate of 1°C / min, then the temperature is reduced to 5°C at a rate of 0.5°C / min, after completion, impurities are removed through a 200 mesh screen, etc., to obtain the agricultural complex insecticide.

[0078] Example 6:

[0079] Preparation of the agricultural complex insecticide:

[0080] First, the agricultural complex insecticide comprises the following mass percentage raw materials:

[0081] benzyl chlorpyrifos 2.5%;

[0082] flonicamid 6.5%;

[0083] PVP / VAc-g-C prepared in Example 3 18 copolymer 3.0%;

[0084] sodium lauroyl sarcosinate 3.0%;

[0085] Xanthan gum 0.22%;

[0086] Glycerol 8.0%;

[0087] The balance is deionized water.

[0088] Then, the preparation method of the agricultural compound insecticide comprises the following steps:

[0089] According to the mass percentage, each raw material is weighed, 70% of the total amount of glycerol (medical grade) and PVP / VAc-g-C 18 copolymer prepared in Example 3 are added to the reaction kettle, the system is heated to 48℃, and low-speed stirring is carried out at 300rpm for 2h, then permethrin (technical ≥96%) and flonicamid (technical ≥97%) are added, after the addition is completed, the system is heated to 57℃, then sodium lauroyl sarcosinate (purity ≥97.0%) is added, after the addition is completed, stirring is carried out at 800rpm for 10min, then the speed is reduced to 500rpm for stirring for 20min, then the temperature is reduced to 40℃ at a cooling rate of 1℃ / min, then xanthan gum (food grade) and the remaining 30% glycerol are added, and stirring is carried out at 400rpm for 20min to obtain a mixture, then the mixture is transferred to an emulsifying tank, deionized water preheated to 40℃ is added to the emulsifying tank, and then a stepwise cooling emulsification process is carried out: the temperature is reduced from 40℃ to 30℃ at a cooling rate of 2℃ / min, then the temperature is reduced to 25℃ at a cooling rate of 1℃ / min, and then the temperature is reduced to 5℃ at a cooling rate of 0.5℃ / min, after completion, impurities are removed through a 200 mesh screen, and an agricultural compound insecticide is obtained.

[0090] Comparative Example 4:

[0091] Comparative Example 4 is a control group of Example 5, and the PVP / VAc-g-C 18 copolymer prepared in Example 2 in Example 5 is replaced by the PVP / VAc-g-C 18 copolymer prepared in Comparative Example 1, and the rest of the raw materials, the raw material amount and the preparation steps remain consistent with those in Example 5, and finally an agricultural compound insecticide is obtained.

[0092] Comparative Example 5:

[0093] Comparative Example 5 is a control group of Example 5, and the PVP / VAc-g-C 18 copolymer prepared in Example 2 in Example 5 is replaced by the PVP / VAc-g-C 18 copolymer prepared in Comparative Example 2, and the rest of the raw materials, the raw material amount and the preparation steps remain consistent with those in Example 5, and finally an agricultural compound insecticide is obtained.

[0094] Comparative Example 6:

[0095] Comparative Example 6 is a control group of Example 5, in which the PVP / VAc-g-C 18 copolymer is replaced with the PVP / VAc copolymer prepared in Comparative Example 3, and the remaining raw materials, the amounts of the raw materials, and the preparation steps are consistent with those in Example 5, and finally an agricultural complex pesticide is obtained.

[0096] Comparative Example 7:

[0097] Comparative Example 7 is a control group of Example 5, in which the PVP / VAc-g-C 18 copolymer prepared in Example 2 in Example 5 is removed, and the remaining raw materials, the amounts of the raw materials, and the preparation steps are consistent with those in Example 5, and finally an agricultural complex pesticide is obtained.

[0098] Comparative Example 8:

[0099] Comparative Example 8 is a control group of Example 5, in which the sodium lauroyl sarcosinate in Example 5 is removed, and the remaining raw materials, the amounts of the raw materials, and the preparation steps are consistent with those in Example 5, and finally an agricultural complex pesticide is obtained.

[0100] Comparative Example 9:

[0101] Comparative Example 9 is a control group of Example 5, in which the stepwise cooling emulsification process in Example 5 is replaced with a cooling process from 40°C to 10°C at a cooling rate of 2°C / min, and the remaining raw materials, the amounts of the raw materials, and the preparation steps are consistent with those in Example 5, and finally an agricultural complex pesticide is obtained. The specific preparation steps are as follows:

[0102] First, the agricultural complex pesticide includes the following raw materials in mass percentage:

[0103] Bifenthrin 2.2%;

[0104] Flonicamid 6.0%;

[0105] PVP / VAc-g-C 18 copolymer prepared in Example 2 in Example 5 is removed, and the remaining raw materials, the amounts of the raw materials, and the preparation steps are consistent with those in Example 5, and finally an agricultural complex pesticide is obtained.

[0106] Sodium lauroyl sarcosinate 2.5%;

[0107] Xanthan gum 0.20%;

[0108] Glycerol 7.0%;

[0109] The balance is deionized water.

[0110] Then, the preparation method of the agricultural complex pesticide includes the following steps:

[0111] The raw materials were weighed according to the mass percentage, and 70% of the total amount of glycerol (medical grade) and PVP / VAc-g-C prepared in Example 2 was added to the reaction kettle. 18 The copolymer was prepared by adding benzotraclothrin (≥96% of technical material) and flonicamid (≥97% of technical material) to the system, which was then heated to 55°C. After the addition was complete, sodium lauroyl sarcosinate (purity ≥97.0%) was added to the system, which was then stirred at 800 rpm for 10 min, then at 500 rpm for 20 min, and then cooled to 40°C at a rate of 1°C / min. Xanthan gum (food grade) and the remaining 30% glycerol were then added to the system, which was then stirred at 400 rpm for 20 min. The mixture was then transferred to an emulsification tank, and deionized water preheated to 40°C was added to the tank. The temperature was then decreased from 40°C to 10°C at a rate of 2°C / min. After the process was complete, the impurities were removed by passing the mixture through a 200-mesh sieve, and the agricultural complex insecticide was obtained.

[0112] Test Example 1:

[0113] The performance of the agricultural complex insecticide (hereinafter referred to as "insecticide") prepared in Examples 4-6 and Comparative Examples 4-9 was tested, and the test results are shown in Table 1.

[0114] (1) Low-temperature precipitation rate:

[0115] Method: 10 mL of the insecticide was refrigerated at 5°C for 7 days, then centrifuged (4000 rpm, 10 min), then dried and weighed, and the low-temperature precipitation rate was calculated:

[0116] Low-temperature precipitation rate = (precipitate mass / insecticide total mass) x 100%;

[0117] (2) Leaf retention rate:

[0118] Method: Cabbage leaves were sprayed with 0.2 mL of the insecticide, then left to stand for 2 h (25°C, 60% humidity), then washed with deionized water, and the amount of insecticide eluted in the washing solution was determined by HPLC, and the leaf retention rate was calculated:

[0119] Leaf retention rate = [(initial insecticide amount - elution amount) / initial insecticide amount] x 100%;

[0120] (3) Cotton bollworm / aphid mortality rate:

[0121] Method: 30 three-age cotton bollworm / aphid nymphs were taken and sprayed with a dilution of the insecticide (diluted 1000 times), and then incubated at 25°C for 72 h. The mortality rate of the cotton bollworm / aphid was then calculated.

[0122] Table 1 Test results:

[0123]

[0124] From the data analysis of Table 1, it can be concluded that:

[0125] 1. Analysis of low-temperature precipitation rate:

[0126] (1) Comparison of Examples 4-6:

[0127] The precipitation rate of Example 4 (SMA = 18g) was 0.8%, which decreased to the lowest value of 0.3% in Example 5 (SMA = 20g), while Example 6 (SMA = 22g) increased to 1.2%. This indicates that there is an optimal range of SMA dosage (18-22g): too low (such as 18g) leads to insufficient inclusion capacity, and too high (such as 22g) causes slight phase separation, both of which will increase the precipitation rate. The increasing concentration of pesticides (6.8% in Example 4 and 9.0% in Example 6) further exacerbates the risk of precipitation.

[0128] (2) Verification of key points by comparative examples:

[0129] Comparative Example 4 (SMA = 15g): The precipitation rate was 1.8%, which was 500% higher than that of Example 5, proving that the anchoring ability is severely insufficient when SMA < 18g.

[0130] Comparative Example 5 (SMA = 25g): The precipitation rate was 5.2%, which increased by 17 times compared to Example 5, confirming that excessive SMA leads to phase separation.

[0131] Comparative Example 7 (without polymer): The precipitation rate was 6.0%, which increased by 19 times compared to Example 5, highlighting the irreplaceable role of PVP / VAc-g-C 18 copolymer in inclusion.

[0132] Comparative Example 9 (without stepwise cooling): The precipitation rate was 4.5%, which increased by 14 times compared to Example 5, proving the core role of the stepwise cooling process in inhibiting crystallization.

[0133] Conclusion: The SMA content (18-22g) and the stepwise cooling process synergistically solve the problem of low-temperature precipitation.

[0134] 2. Analysis of leaf surface retention rate:

[0135] (1) Comparison of Examples 4-6:

[0136] Example 5 had the highest retention rate (86%), Example 4 (SMA = 18g) had a shorter C 18 chain, resulting in weaker anchoring force (78%), and Example 6 (SMA = 22g) decreased to 82% due to slight phase separation. This proves that SMA = 20g is the optimal anchoring strength.

[0137] (2) Key points of the comparative examples:

[0138] Comparative Example 4 (SMA = 15 g): Retention rate 68%, 20.9% lower than Example 5, confirming that short C 18 chain cannot effectively penetrate the wax layer.

[0139] Comparative Example 5 (SMA = 25 g): Retention rate 50%, 41.9% lower than Example 5, excessive SMA causes aggregation, leading to uneven distribution of drug solution.

[0140] Comparative Example 6 (no C 18 chain): Retention rate 42%, 51.2% lower than Example 5, directly proving the necessity of C 18 hydrophobic chain for wax anchoring.

[0141] Comparative Example 7 (no polymer): Retention rate 45%, 47.7% lower than Example 5, missing the overall anchoring system leads to functional collapse.

[0142] Comparative Example 8 (no lauroyl sarcosine sodium): Retention rate 65%, 24.4% lower than Example 5, indicating that the synergistic effect of amphoteric surfactant on spreading is indispensable.

[0143] Conclusion: PVP / VAc-g-C 18 copolymer's C 18 chain and lauroyl sarcosine sodium form a double synergistic mechanism, breaking through the technical bottleneck of permeability.

[0144] 3. Insecticidal efficacy analysis:

[0145] (1) Cotton bollworm mortality rate:

[0146] Example 5 reached a peak of 95%, directly related to its low release rate (0.3%) and high retention rate (86%).

[0147] Comparative Example 5 (SMA = 25 g) due to high release rate (5.2%) and low retention rate (50%), mortality rate dropped to 76% (20% reduction).

[0148] Comparative Example 7 (no polymer) due to drug failure, mortality rate dropped to a minimum of 75% (21.1% reduction).

[0149] (2) Aphid mortality rate:

[0150] Example 5 reached 93%, relying on the effective penetration of flonicamid.

[0151] Comparative Example 6 (no C 18 chain) due to the sudden drop in nicotine retention rate, mortality rate was only 78% (16.1% reduction).

[0152] Comparative Example 8 (without lauroylsarcosine sodium) due to insufficient penetration of pyrethroid, the mortality rate dropped to 82% (a decrease of 11.8%).

[0153] Pharmacodynamic attenuation law:

[0154] Cotton bollworm control relies more on physical stability (excretion rate dominant), such as Comparative Example 7 high excretion rate directly leading to a 21.1% decrease in mortality rate.

[0155] Aphid control relies more on chemical penetration (retention rate dominant), such as Comparative Example 6 without C 18 chain retention rate dropped by 51.2%, resulting in a 16.1% decrease in mortality rate.

[0156] It should be noted that in this article, such as the term "includes, contains" or any other variant is intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or also includes the elements inherent to such process, method, article or equipment.

[0157] Although embodiments of the present application have been shown and described, it will be understood by those having ordinary skill in the art that various changes, modifications, substitutions and alterations can be made hereto without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. An agroformulatable insecticide, characterized in that, The following raw materials are included by mass percentage: Benzyl chlorpyrifos 1.8%~2.5%; Flonicamid 5.0%~6.5%; PVP / VAc-g-C18 copolymer 2.2%~3.0%; Sodium lauroyl methylamino acid 2.0%~3.0%; Xanthan gum 0.18%~0.22%; Glycerol 6.0%~8.0%; The balance is deionized water; The PVP / VAc-g-C18 copolymer is prepared by the following steps: N-vinyl pyrrolidone, vinyl acetate, methyl methacrylate octadecyl ester and azobisisobutyronitrile are added to anhydrous ethanol. After completion, nitrogen is filled into the system, the nitrogen protection flow rate is maintained at 0.2 L / min, and gradient temperature polymerization is carried out. After completion, the reaction solution is quickly poured into n-hexane at -20°C, and the mixture is allowed to stand for 2-4 h. The precipitate is filtered and then subjected to supercritical CO2 extraction. After extraction is completed, the product is vacuum dried for 12 h. After completion, the PVP / VAc-g-C18 copolymer is obtained. The preparation method of the agricultural compound insecticide comprises the following steps: According to the mass percentage, each raw material is weighed and added to a reaction kettle with 70% of the total amount of glycerol and PVP / VAc-g-C18 copolymer. The system is heated to 45-48°C and stirred at 300 rpm for 1-2 h. Then benzyl chlorpyrifos and flonicamid are added. After addition is completed, the system is heated to 55-57°C. Sodium lauroyl methylamino acid is then added. After addition is completed, the system is stirred at 800 rpm for 10 min, then the stirring speed is reduced to 500 rpm for 20 min, and then the temperature is reduced to 40°C at a rate of 1°C / min. Xanthan gum and the remaining 30% of glycerol are then added. The mixture is stirred at 400 rpm for 15-20 min, and then transferred to an emulsifying tank. Deionized water preheated to 40°C is added to the emulsifying tank, and then a stepwise cooling emulsification process is carried out. After completion, the mixture is passed through a 200 mesh screen to obtain the agricultural compound insecticide. The stepwise cooling emulsification process is as follows: the temperature is reduced from 40°C to 30°C at a rate of 2°C / min, then to 25°C at a rate of 1°C / min, and then to 5°C at a rate of 0.5°C / min.

2. The agroformulatable insecticide as claimed in claim 1, wherein, The agricultural compound insecticide comprises the following raw materials by mass percentage: Benzyl chlorpyrifos 2.2%; Flonicamid 6.0%; PVP / VAc-g-C18 copolymer 2.8%; Sodium lauroyl methylamino acid 2.5%; Xanthan gum 0.20%; Glycerol 7.0%; The balance is deionized water.

3. The agroformulatable insecticide as claimed in claim 1, wherein, The amount ratio of anhydrous ethanol, N-vinyl pyrrolidone, vinyl acetate, methyl methacrylate octadecyl ester and azobisisobutyronitrile is 500 mL:45 g:30 g:18-22 g:0.8-1.0 g.

4. The agroformulatable insecticide as claimed in claim 1, wherein, The gradient temperature polymerization is as follows: first, the temperature is increased to 40-50°C, and then stirred at constant temperature for 20-30 min. Then the temperature is increased to 62-65°C, and stirred at constant temperature for 3 h. Then the temperature is increased to 72°C, and stirred at constant temperature for 1-2 h.

5. The agroformulatable insecticide as claimed in claim 1, wherein, The supercritical CO2 extraction: the extraction pressure is set to 30-35 MPa, the temperature is set to 45-50 DEG C, the CO2 flow rate is set to 10-12 kg / h, and the extraction time is 120 min.

6. A method of preparing an agroformulated insecticide according to any one of claims 1 to 5, characterized in that, It comprises the following steps: According to the mass percentage, each raw material is weighed, 70% of the total amount of glycerol and PVP / VAc-g-C18 copolymer is added into a reaction kettle, the system is heated to 45-48 DEG C, and is stirred at a low speed of 300 rpm for 1-2 h, then benzothiocyanate and flonicamid are added, after the addition, the system is heated to 55-57 DEG C, then lauroylsarcosine sodium is added, after the addition, stirring is carried out at 800 rpm for 10 min, then the speed is reduced to 500 rpm for stirring for 20 min, then the temperature is reduced to 40 DEG C at a rate of 1 DEG C / min, then xanthan gum and the remaining 30% of glycerol are added, stirring is carried out at 400 rpm for 15-20 min, a mixture is obtained, the mixture is transferred to an emulsifying tank, deionized water preheated to 40 DEG C is added into the emulsifying tank, then a stepwise cooling emulsification process is carried out, after the process, the mixture is filtered through a 200-mesh screen, and an agricultural compound insecticide is obtained; The stepwise cooling emulsification process: the temperature is reduced from 40 DEG C to 30 DEG C at a rate of 2 DEG C / min, then the temperature is reduced to 25 DEG C at a rate of 1 DEG C / min, and then the temperature is reduced to 5 DEG C at a rate of 0.5 DEG C / min.

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