A microemulsion containing fluroxypyr-meptyl and clopyralid and a method for preparing the same

Abstract

The present application relates to the technical field of pesticide preparation, in particular to a microemulsion containing fluroxypyr-isooctyl and aminoclopidol and a preparation method thereof, which is composed of the following components in percentage by mass: fluroxypyr-isooctyl 1-15%, aminoclopidol 1-15%, composite emulsifier 10-22%, co-emulsifier 5-11%, composite solvent 15-28%, antifreezing agent 2-6%, stabilizer 0.5-2.5%, and deionized water, with the total being 100%. The composite emulsifier is composed of dioctyl sodium sulfosuccinate and triphenyl ethenyl phenol polyoxyethylene ether phosphate triethanolamine salt, the composite solvent is composed of N,N-dimethyl decanamide and ethylene glycol diacetate, the stabilizer is composed of epoxidized soybean oil and citric acid, the co-emulsifier is dipropylene glycol methyl ether, and the antifreezing agent is glycerol. The microemulsion containing fluroxypyr-isooctyl and aminoclopidol and the preparation method thereof effectively solve a plurality of technical problems in the compounding process of the two active ingredients and have significant technical advantages.

Description

Technical Field

[0001] This invention relates to the field of pesticide preparation technology, specifically to a microemulsion containing isooctyl fluoride and aminopyridine, and its preparation method. Background Technology

[0002] The widespread proliferation of broadleaf weeds in farmland can seriously affect crop growth, reduce field yield and quality, and make efficient control of broadleaf weeds a crucial aspect of agricultural production. Fluorine isooctyl ester and aminopyridine are commonly used active pesticide ingredients for controlling broadleaf weeds. Both exhibit good efficacy against different types of broadleaf weeds, but their use alone has significant limitations: a narrow spectrum of control, poor efficacy against some annual or perennial broadleaf weeds, and a short duration of effectiveness, requiring multiple applications to achieve the desired results, thus increasing labor and pesticide costs in agricultural production.

[0003] To improve this situation, the combination of two active ingredients has become a research focus. However, the two have significantly different physicochemical properties, and the combination process faces many technical challenges. Existing emulsification systems are difficult to adapt to the lipophilic and hydrophilic properties of the two components at the same time, which can easily lead to insufficient emulsification and system stratification. A single solvent cannot meet the dissolution and dispersion requirements of both, which can easily cause crystallization and uneven dissolution.

[0004] Meanwhile, both active ingredients are prone to hydrolysis and photolysis during storage and use, and existing stabilizers cannot provide dual protection, leading to rapid efficacy decay. Furthermore, current preparation processes mostly employ direct mixing, lacking targeted emulsification control strategies, which easily results in uneven microemulsion particle size, affecting the formulation's stability and field application efficacy. Currently, there is no effective microemulsion formulation combining isooctyl fluoride and aminopyridine phosphate that can solve the above problems. Therefore, developing a stable and highly effective microemulsion formulation and its corresponding preparation method has become an urgent need in the field of agricultural pesticide formulation. Summary of the Invention

[0005] The primary objective of this invention is to provide a microemulsion containing isooctyl fluoride and aminopyridine, and a method for its preparation.

[0006] A further objective of this invention is to provide a microemulsion containing isooctyl fluoride and aminopyridine, comprising, by mass percentage, the following components: 1%-15% isooctyl fluoride, 1%-15% aminopyridine, 10%-22% composite emulsifier, 5%-11% co-emulsifier, 15%-28% composite solvent, 2%-6% antifreeze, 0.5%-2.5% stabilizer, and deionized water to 100%; wherein the composite emulsifier is composed of sodium dioctyl succinate sulfonate and tristyrene-phenylphenol polyoxyethylene ether phosphate triethanolamine salt, the composite solvent is composed of N,N-dimethyldecylamide and ethylene glycol diacetate, the stabilizer is composed of epoxidized soybean oil and citric acid, the co-emulsifier is dipropylene glycol methyl ether, and the antifreeze is glycerol.

[0007] Preferably, the mass ratio of epoxidized soybean oil to citric acid in the stabilizer is 3:1.

[0008] Preferably, the mass ratio of sodium dioctyl succinate sulfonate to tristyrene-phenylphenol polyoxyethylene ether phosphate triethanolamine salt in the composite emulsifier is 1:1, 2:1, 3:1 or 5:1.

[0009] Preferably, the mass ratio of N,N-dimethyldecanoate to ethylene glycol diacetate in the composite solvent is 1:2, 1:3, or 1:4.

[0010] Preferably, by mass percentage, it contains 5% isooctyl fluoride, 3% aminopyridine acid, 15%-18% compound emulsifier, 8% co-emulsifier, 20% compound solvent, 4% antifreeze, and 1.5% stabilizer.

[0011] Preferably, by mass percentage, it contains 3% isooctyl fluoride, 1% aminopyridine acid, 12% compound emulsifier, 6% co-emulsifier, 18% compound solvent, 3% antifreeze, and 1% stabilizer.

[0012] Preferably, by mass percentage, it contains 10%-15% isooctyl fluoride, 5%-15% aminopyridine acid, 20%-22% compound emulsifier, 10%-11% co-emulsifier, 22%-28% compound solvent, 5%-6% antifreeze, and 2%-2.5% stabilizer.

[0013] A method for preparing the aforementioned fluoride-containing isooctyl ester and ampicillin microemulsion includes the following steps: Step 1, Preparation of oil phase: Add isooctyl fluoride to the composite solvent, place it in a constant temperature water bath at 55℃-65℃, stir at 280 rpm-350 rpm until completely dissolved, add the full amount or half amount of composite emulsifier, and continue stirring for 15 minutes-20 minutes to obtain a uniform oil phase; Step 2, Preparation of aqueous phase: Add aminopyridine acid, co-emulsifier, antifreeze and stabilizer to deionized water, place in a constant temperature water bath at 52℃-58℃, and stir at 220 rpm-280 rpm until completely dissolved to obtain a homogeneous aqueous phase; Step 3, Mixing and Emulsification: Add the aqueous phase dropwise to the oil phase at a rate of 0.8 mL / min to 1.5 mL / min. During the dropwise addition, maintain the oil phase temperature at 55℃ to 65℃ and the stirring speed at 350 rpm to 420 rpm. After the dropwise addition is complete, continue stirring for 18 to 30 minutes. If half of the composite emulsifier was added in Step 1, add the remaining half of the composite emulsifier at this time, adjust the stirring speed to 380 rpm to 450 rpm and continue stirring for 18 to 25 minutes. Cool to room temperature, filter to remove insoluble impurities, and obtain the microemulsion.

[0014] Preferably, the constant temperature water bath temperature for preparing the oil phase in step one is 60℃-63℃, and the stirring speed for dissolving isooctyl fluoride is 300 rpm-350 rpm.

[0015] Preferably, in step two, the constant temperature water bath for preparing the aqueous phase is 55℃-58℃, and the stirring speed for dissolving each component is 250 rpm-280 rpm.

[0016] Compared with the prior art, the beneficial effects of the present invention are: 1. The microemulsion containing isooctyl fluoride and aminopyridine acid and its preparation method provided by the present invention effectively solves a number of technical problems in the compounding process of the two active ingredients and has significant technical advantages. The present invention, by combining a composite emulsifier in a specific compounding form, accurately adapts to the physicochemical properties of the two active ingredients, effectively reduces the interfacial tension between the components, completely solves the core problem of poor compatibility between the two, and achieves stable emulsification of the system.

[0017] 2. The reasonable combination of composite solvents in this invention takes into account the dissolution and dispersion requirements of the two active ingredients, avoids problems such as crystallization and insufficient dissolution caused by a single solvent, and ensures the appearance uniformity and system stability of the formulation.

[0018] 3. The compound stabilizer of this invention achieves targeted protection of the two active ingredients, inhibiting the hydrolysis of isooctyl fluoride and the photolysis of ampicillin, respectively, delaying the decline of efficacy, and greatly improving the storage stability of the formulation.

[0019] 4. The stepwise preparation and controlled-rate dripping process designed in this invention optimizes the mixing and emulsification process of the oil and aqueous phases, resulting in a more uniform microemulsion particle size distribution. This significantly improves the centrifugal stability, cold and heat storage stability, and dilution stability of the formulation, ensuring its effectiveness in field dilution. The combination of the two active ingredients achieves synergistic effects, effectively broadening the control spectrum and improving the control efficacy and duration of action against various broadleaf weeds. Furthermore, the formulation exhibits good crop safety with no adverse effects.

[0020] 5. The preparation process of this invention is simple and controllable, and the process parameters are highly adaptable. The active ingredient ratio can be adjusted according to the different weed control needs in the field, making it suitable for large-scale industrial production and possessing high practical agricultural application value. Detailed Implementation

[0021] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example 1:

[0022] The raw material composition by mass percentage is as follows: 5% isooctyl fluoride, 3% aminopyridine acid, 15% compound emulsifier, 10% sodium dioctyl succinate sulfonate, 5% tristyrene-phenol polyoxyethylene ether phosphate triethanolamine salt, 8% co-emulsifier, 20% compound solvent, 5% N,N-dimethyldecylamide, 15% ethylene glycol diacetate, 4% antifreeze, 1.5% stabilizer, 1.12% epoxidized soybean oil, 0.37% citric acid, and deionized water to bring the total to 100%.

[0023] Preparation method: The first step is to prepare the oil phase by adding isooctyl fluoride ester to the composite solvent and placing it in a 60°C constant temperature water bath. Stirring at 300 rpm until completely dissolved, then adding half the amount of composite emulsifier and stirring for another 15 minutes to obtain a homogeneous oil phase. The second step is to prepare the aqueous phase by adding aminochloropyridine acid, co-emulsifier, antifreeze and stabilizer to deionized water, placing it in a 55°C constant temperature water bath, and stirring at 250 rpm until completely dissolved to obtain a homogeneous aqueous phase. The third step is mixing and emulsification. The aqueous phase is slowly added dropwise to the oil phase at a rate of 1 ml per minute. During the dropwise addition, the oil phase temperature is maintained at 60 degrees Celsius and the stirring speed is 350 rpm. After the dropwise addition is completed, stirring is continued for 30 minutes. Then, the remaining 1 / 2 of the composite emulsifier is slowly added, the stirring speed is adjusted to 400 rpm, and stirring is continued for 20 minutes. The mixture is then cooled to room temperature and filtered to remove insoluble impurities, resulting in a microemulsion containing isooctyl fluoride and aminopyridine.

[0024] The composite emulsifier contains sodium dioctyl succinate sulfonate and tristyrene-phenylphenol polyoxyethylene ether phosphate triethanolamine salt in a 2:1 mass ratio, with an HLB value of 14.2. This is suitable for oil-in-water microemulsion systems and effectively reduces the interfacial tension between isooctyl fluoride and aminopyridine acid, resolving their poor compatibility. The composite solvent contains N,N-dimethyldecamide and ethylene glycol diacetate in a 1:3 mass ratio. N,N-dimethyldecamide fully dissolves isooctyl fluoride, while ethylene glycol diacetate effectively disperses aminopyridine acid, avoiding insufficient dissolution and crystallization problems caused by a single solvent. The co-emulsifier is dipropylene glycol methyl ether, which helps improve the emulsification effect. The antifreeze agent is glycerol, which lowers the freezing point of the microemulsion. The stabilizer contains epoxidized soybean oil and citric acid in a 3:1 mass ratio, which inhibit the hydrolysis of isooctyl fluoride and the photolysis of aminopyridine acid, respectively, extending shelf life and efficacy stability. Example 2:

[0025] The raw material composition by mass percentage is as follows: 5% isooctyl fluoride, 3% aminopyridine acid, 18% compound emulsifier, 12% sodium dioctyl succinate sulfonate, 6% tristyrene-phenol polyoxyethylene ether phosphate triethanolamine salt, 8% co-emulsifier, 20% compound solvent, 5% N,N-dimethyldecylamide, 15% ethylene glycol diacetate, 4% antifreeze, 1.5% stabilizer, 1.12% epoxidized soybean oil, 0.37% citric acid, and deionized water to bring the total to 100%.

[0026] Preparation method: The first step is to prepare the oil phase by adding isooctyl fluoride ester to the composite solvent and placing it in a 60°C constant temperature water bath. The mixture is stirred at 350 rpm until completely dissolved. Then, all the composite emulsifier is added and the mixture is stirred for another 20 minutes to obtain a homogeneous oil phase. The second step, preparing the aqueous phase, is completely consistent with Example 1. The third step involves mixing and emulsifying the aqueous phase. The aqueous phase is slowly added dropwise to the oil phase at a rate of 1.5 ml per minute. During the addition, the oil phase temperature is maintained at 60 degrees Celsius and the stirring speed is 350 rpm. After the addition is complete, stirring is continued for 25 minutes. The stirring speed is then adjusted to 450 rpm and stirring is continued for another 25 minutes. The mixture is then cooled to room temperature and filtered to remove insoluble impurities, yielding a microemulsion containing isooctyl fluoride and aminopyridine.

[0027] Based on Example 1, this embodiment optimizes the dosage and addition method of the composite emulsifier. The mass ratio of the two components in the composite emulsifier remains 2:1, but the dosage is increased from 15 to 18. The addition method is changed from adding in two parts to adding at once. At the same time, the stirring speed of the oil phase is adjusted to 350 revolutions per minute. The remaining raw materials and process details are the same as in Example 1. Example 3:

[0028] The raw material composition by mass percentage is as follows: 5% isooctyl fluoride, 3% aminopyridine acid, 15% compound emulsifier, 7.5% sodium dioctyl succinate sulfonate, 7.5% tristyrene-phenylphenol polyoxyethylene ether phosphate triethanolamine salt, 8% co-emulsifier, 20% compound solvent, 5% N,N-dimethyldecylamide, 15% ethylene glycol diacetate, 4% antifreeze, 1.5% stabilizer, 1.12% epoxidized soybean oil, 0.37% citric acid, and deionized water to bring the total to 100%.

[0029] Preparation method: completely consistent with Example 1.

[0030] Based on Example 1, this embodiment adjusts the internal ratio of the composite emulsifier. The mass ratio of sodium dioctyl succinate sulfonate to tristyrene-phenylphenol polyoxyethylene ether phosphate triethanolamine salt is changed to 1:1, and the HLB value is reduced to 13.8, making the microemulsion particle size distribution more uniform and further improving the stability of the system. The remaining raw material ratios and preparation processes are the same as in Example 1. Example 4:

[0031] The raw material composition by mass percentage is as follows: 5% isooctyl fluoride, 3% aminopyridine acid, 15% compound emulsifier, 10% sodium dioctyl succinate sulfonate, 5% tristyrene-phenol polyoxyethylene ether phosphate triethanolamine salt, 8% co-emulsifier, 25% compound solvent, 5% N,N-dimethyldecylamide, 20% ethylene glycol diacetate, 4% antifreeze, 1.5% stabilizer, 1.12% epoxidized soybean oil, 0.37% citric acid, and deionized water to bring the total to 100%.

[0032] Preparation method: The first step is to prepare the oil phase by adding isooctyl fluoride ester to the composite solvent and placing it in a 65°C constant temperature water bath. Stirring at 320 rpm until completely dissolved, then adding half the amount of composite emulsifier and stirring for another 15 minutes to obtain a homogeneous oil phase. The second step, preparing the aqueous phase, is completely consistent with Example 1. The third step, mixing and emulsification, is completely consistent with Example 1.

[0033] Based on Example 1, this embodiment optimizes the amount and internal ratio of the composite solvent. The mass ratio of N,N-dimethyldecylamide to ethylene glycol diacetate in the composite solvent is changed to 1:4, and the amount is increased from 20 to 25. At the same time, the oil phase preparation temperature is adjusted to 65 degrees Celsius to ensure complete dissolution of isooctyl fluoride. The remaining raw materials and processes are the same as in Example 1 to ensure that the preparation process is stable and repeatable. Example 5:

[0034] The raw material composition by mass percentage is as follows: 10g isooctyl fluoride, 5g aminopyridine acid, 20g compound emulsifier, 13.3g sodium dioctyl succinate sulfonate, 6.7g tristyrene-phenylphenol polyoxyethylene ether phosphate triethanolamine salt, 10g co-emulsifier, 22g compound solvent, 7.3g N,N-dimethyldecylamide, 14.7g ethylene glycol diacetate, 5g antifreeze, 2g stabilizer, 1.5g epoxidized soybean oil, 0.5g citric acid, and deionized water to 100g.

[0035] Preparation method: The first step is to prepare the oil phase by adding isooctyl fluoride ester to the composite solvent and placing it in a 62°C constant temperature water bath. Stir at 350 rpm for 20 minutes until completely dissolved. Then, add half the amount of composite emulsifier and continue stirring for 15 minutes to obtain a homogeneous oil phase. The second step is to prepare the aqueous phase by adding aminochloropyridine acid, co-emulsifier, antifreeze and stabilizer to deionized water, placing it in a 58°C constant temperature water bath, and stirring at 280 rpm until completely dissolved to obtain a homogeneous aqueous phase. The third step involves mixing and emulsifying. The aqueous phase is slowly added dropwise to the oil phase at a rate of 1.2 ml per minute. During the addition, the oil phase temperature is maintained at 62 degrees Celsius and the stirring speed is 350 rpm. After the addition is complete, stirring is continued for 25 minutes. Then, the remaining half of the composite emulsifier is slowly added, and the stirring speed is adjusted to 420 rpm. Stirring is continued for 25 minutes. The mixture is then cooled to room temperature and filtered to remove insoluble impurities, yielding a microemulsion containing isooctyl fluoride and aminopyridine.

[0036] This embodiment addresses the needs of crop fields with high weed density by increasing the dosage of two active ingredients: isooctyl fluoride is increased to 10 and aminopyridine is increased to 5. The dosages of compound emulsifier, co-emulsifier, compound solvent, and stabilizer are adjusted accordingly. The mass ratio of the two components in the compound emulsifier remains 2:1, the mass ratio of N,N-dimethyldecylamide to ethylene glycol diacetate in the compound solvent is 1:2, and the mass ratio of the two components in the stabilizer remains 3:1. At the same time, the preparation process parameters are optimized by increasing the stirring speed and temperature to avoid problems such as stratification and incomplete emulsification when compounding high-content active ingredients. Example 6:

[0037] The raw material composition by mass percentage is as follows: 3g isooctyl fluoride, 1g aminopyridine acid, 12g compound emulsifier, 8g sodium dioctyl succinate sulfonate, 4g tristyrene-phenol polyoxyethylene ether phosphate triethanolamine salt, 6g co-emulsifier, 18g compound solvent, 6g N,N-dimethyldecylamide, 12g ethylene glycol diacetate, 3g antifreeze, 1g stabilizer, 0.75g epoxidized soybean oil, 0.25g citric acid, and deionized water to bring the total to 100g.

[0038] Preparation method: The first step is to prepare the oil phase by adding isooctyl fluoride to the composite solvent and placing it in a 58°C constant temperature water bath. Stirring at 280 rpm until completely dissolved, then adding half the amount of composite emulsifier and stirring for another 15 minutes to obtain a homogeneous oil phase. The second step is to prepare the aqueous phase by adding aminochloropyridine acid, co-emulsifier, antifreeze and stabilizer to deionized water, placing it in a 52-degree Celsius constant temperature water bath, and stirring at 220 rpm until completely dissolved to obtain a homogeneous aqueous phase. The third step involves mixing and emulsifying. The aqueous phase is slowly added dropwise to the oil phase at a rate of 0.8 mL per minute. During the addition, the oil phase temperature is maintained at 58 degrees Celsius and the stirring speed is 350 rpm. After the addition is complete, stirring is continued for 18 minutes. Then, the remaining half of the composite emulsifier is slowly added, and the stirring speed is adjusted to 380 rpm. Stirring is continued for 18 minutes. The mixture is then cooled to room temperature and filtered to remove insoluble impurities, yielding a microemulsion containing isooctyl fluoride and aminopyridine.

[0039] This embodiment addresses the needs of fields with low weed density or sensitive crops by reducing the dosage of two active ingredients and various adjuvants. The dosage of isooctyl fluoride is reduced to 3, and that of aminopyridine is reduced to 1. The mass ratio of the two components in the compound emulsifier remains 2:1. The mass ratio of N,N-dimethyldecylamide to ethylene glycol diacetate in the compound solvent is 1:2. The mass ratio of the two components in the stabilizer remains 3:1. The stirring speed and temperature are optimized to avoid problems such as insufficient emulsification of low-content active ingredients and system turbidity. Example 7:

[0040] The raw material composition by mass percentage is as follows: 15% isooctyl fluoride, 10% aminochloropyridine acid, 22% compound emulsifier, 16.5% sodium dioctyl succinate sulfonate, 5.5% tristyrene-phenylphenol polyoxyethylene ether phosphate triethanolamine salt, 11% co-emulsifier, 28% compound solvent, 7% N,N-dimethyldecylamide, 21% ethylene glycol diacetate, 6% antifreeze, 2.5% stabilizer, 1.875% epoxidized soybean oil, 0.625% citric acid, and deionized water to bring the total to 100%.

[0041] Preparation method: The first step is to prepare the oil phase. Fluorine isooctyl ester is added to the composite solvent and placed in a 63°C constant temperature water bath. It is stirred at 340 rpm for 20 minutes until completely dissolved. Then, half of the amount of composite emulsifier is added and stirring is continued for 18 minutes to obtain a homogeneous oil phase. The second step is to prepare the aqueous phase by adding aminochloropyridine acid, co-emulsifier, antifreeze and stabilizer to deionized water, placing it in a 56-degree Celsius constant temperature water bath, and stirring at 260 rpm until completely dissolved to obtain a homogeneous aqueous phase. The third step involves mixing and emulsifying. The aqueous phase is slowly added dropwise to the oil phase at a rate of 1.4 ml per minute. During the addition, the oil phase temperature is maintained at 63 degrees Celsius and the stirring speed is 420 rpm. After the addition is complete, stirring is continued for 28 minutes. Then, the remaining half of the composite emulsifier is slowly added, and the stirring speed is adjusted to 440 rpm. Stirring is continued for 22 minutes. The mixture is then cooled to room temperature and filtered to remove insoluble impurities, yielding a microemulsion containing isooctyl fluoride and aminopyridine.

[0042] Based on Example 5, this embodiment further increases the amount of active ingredients, increasing isooctyl fluoride to 15 and aminopyridine to 10, adjusting the internal ratio of the composite emulsifier to 3:1, increasing the amount of composite solvent to 28, and maintaining the mass ratio of the two components in the composite solvent at 1:3. The mass ratio of the two components in the stabilizer remains at 3:1. The preparation process parameters are optimized, and the stirring speed and time are increased to ensure the stability of the system under high content and wide range of auxiliary agent ratios. Example 8:

[0043] The raw material composition by mass percentage is as follows: 1 part isooctyl fluoride, 15 part aminopyridine acid, 10 part compound emulsifier, 8.33 part sodium dioctyl succinate sulfonate, 1.67 part tristyrene-phenylphenol polyoxyethylene ether phosphate triethanolamine salt, 5 part co-emulsifier, 15 part compound solvent, 3 part N,N-dimethyldecylamide, 12 part ethylene glycol diacetate, 2 part antifreeze, 0.5 part stabilizer, 0.375 part epoxidized soybean oil, 0.125 part citric acid, and deionized water to bring the total to 100.

[0044] Preparation method: The first step is to prepare the oil phase. Fluorine isooctyl ester is added to the composite solvent and placed in a 55°C constant temperature water bath. It is stirred at 290 rpm for 18 minutes until completely dissolved. Then, half of the amount of composite emulsifier is added and stirring is continued for 15 minutes to obtain a homogeneous oil phase. The second step is to prepare the aqueous phase by adding aminochloropyridine acid, co-emulsifier, antifreeze and stabilizer to deionized water, placing it in a 53°C constant temperature water bath, and stirring at 230 rpm until completely dissolved to obtain a homogeneous aqueous phase. The third step involves mixing and emulsifying. The aqueous phase is slowly added dropwise to the oil phase at a rate of 0.9 mL per minute. During the addition, the oil phase temperature is maintained at 55 degrees Celsius and the stirring speed is 360 rpm. After the addition is complete, stirring is continued for 20 minutes. Then, the remaining half of the composite emulsifier is slowly added, and the stirring speed is adjusted to 390 rpm. Stirring is continued for 19 minutes. The mixture is then cooled to room temperature and filtered to remove insoluble impurities, yielding a microemulsion containing isooctyl fluoride and aminopyridine.

[0045] This embodiment addresses the needs of crop fields dominated by perennial weeds by adjusting the active ingredients to a specific ratio. The isooctyl fluoride content is reduced to 1, while the aminopyridine acid content is increased to 15. The internal ratio of the compound emulsifier is adjusted to 5:1, while the HLB value remains within the suitable range. The amount of compound solvent is reduced to 15, and the mass ratio of the two components in the compound solvent is 1:4. The mass ratio of the two components in the stabilizer remains 3:1. The preparation process parameters are optimized to ensure stable compounding of the two active ingredients under extreme ratios.

[0046] Comparative Example 1: The raw material composition by mass percentage is as follows: 5% isooctyl fluoride, 3% aminopyridine acid, 15% single emulsifier, 15% sodium dioctyl succinate sulfonate, 8% co-emulsifier, 20% compound solvent, 5% N,N-dimethyldecylamide, 15% ethylene glycol diacetate, 4% antifreeze, 1.5% stabilizer, 1.125% epoxidized soybean oil, 0.375% citric acid, and deionized water to bring the total to 100%.

[0047] Preparation method: completely consistent with Example 1.

[0048] This comparative example did not use the composite emulsifier of the present invention, but only used a single emulsifier, sodium dioctyl succinate sulfonate, with an HLB value of 12.8. It could not simultaneously adapt to the lipophilicity of isooctyl fluoride and the hydrophilicity of aminopyridine acid, resulting in poor emulsification effect, poor stability of the microemulsion system, and inability to achieve stable compounding of the two active ingredients. This is in stark contrast to Example 1, highlighting the necessity of the composite emulsifier.

[0049] Comparative Example 2: The raw material composition by mass percentage is as follows: 5% isooctyl fluoride, 3% aminopyridine acid, 15% compound emulsifier, 10% sodium dioctyl succinate sulfonate, 5% tristyrene-phenol polyoxyethylene ether phosphate triethanolamine salt, 8% co-emulsifier, 20% single solvent, 20% N,N-dimethyldecylamide, 4% antifreeze, 1.5% stabilizer, 1.12% epoxidized soybean oil, 0.37% citric acid, and deionized water to bring the total to 100%.

[0050] Preparation method: completely consistent with Example 1.

[0051] This comparative example did not use the composite solvent of the present invention, but only used the single solvent N,N-dimethyldecylamide, which can only effectively dissolve isooctyl fluoride and cannot fully disperse aminopyridine acid, resulting in insufficient dissolution and crystallization of aminopyridine acid, making the microemulsion cloudy and reducing its stability. Compared with Example 1, this highlights the necessity of the composite solvent.

[0052] Comparative Example 3: The raw material composition by mass percentage is as follows: 5% isooctyl fluoride, 3% aminopyridine acid, 15% compound emulsifier, 10% sodium dioctyl succinate sulfonate, 5% tristyrene-phenol polyoxyethylene ether phosphate triethanolamine salt, 8% co-emulsifier, 20% compound solvent, 5% N,N-dimethyldecylamide, 15% ethylene glycol diacetate, 4% antifreeze, and deionized water to bring the total to 100%.

[0053] Preparation method: completely consistent with Example 1.

[0054] This comparative example did not include the compound stabilizer of the present invention. Fluorine isooctyl ester is easily hydrolyzed during storage, and aminopyridine acid is easily decomposed by ultraviolet light, resulting in decreased storage stability of the microemulsion and significant reduction in efficacy. Compared with Example 1, this highlights the necessity of the compound stabilizer.

[0055] Comparative Example 4: The raw material composition by mass percentage is as follows: 5% isooctyl fluoride, 3% aminopyridine acid, 15% compound emulsifier, 10% sodium dioctyl succinate sulfonate, 5% tristyrene-phenol polyoxyethylene ether phosphate triethanolamine salt, 8% co-emulsifier, 20% compound solvent, 5% N,N-dimethyldecylamide, 15% ethylene glycol diacetate, 4% antifreeze, 1.5% stabilizer, 1.12% epoxidized soybean oil, 0.37% citric acid, and deionized water to bring the total to 100%.

[0056] Preparation method: The oil phase and the water phase are directly mixed and stirred at 400 rpm for 40 minutes. Other parameters are the same as in Example 1.

[0057] This comparative example did not employ the stepwise preparation and rate-controlled dropping process of the present invention. Direct mixing resulted in insufficient emulsification of the oil and water phases, uneven microemulsion particle size, poor system stability, and easy stratification. Compared with Example 1, this highlights the necessity of the stepwise preparation and rate-controlled dropping process.

[0058] Comparative Example 5: The raw material composition by mass percentage is as follows: 25% isooctyl fluoride, 20% aminopyridine acid, 15% compound emulsifier, 10% sodium dioctyl succinate sulfonate, 5% tristyrene-phenol polyoxyethylene ether phosphate triethanolamine salt, 8% co-emulsifier, 20% compound solvent, 5% N,N-dimethyldecylamide, 15% ethylene glycol diacetate, 4% antifreeze, 1.5% stabilizer, 1.12% epoxidized soybean oil, 0.375% citric acid, and deionized water to bring the total to 100%.

[0059] Preparation method: completely consistent with Example 1.

[0060] In this comparative example, the dosage of the two active ingredients was too high, resulting in incomplete emulsification, severe stratification and crystallization of the microemulsion system, which prevented the formation of a stable microemulsion, thus hindering the normal efficacy of the drug and causing phytotoxicity. Compared with Example 1, this highlights the rationality of the raw material ratio of the present invention.

[0061] Comparative Example 6: The raw material composition by mass percentage is as follows: 5% isooctyl fluoride, 8% co-emulsifier, 20% compound solvent, 5% N,N-dimethyldecylamide, 15% ethylene glycol diacetate, 4% antifreeze, 1.5% stabilizer, 1.125% epoxidized soybean oil, 0.375% citric acid, and deionized water to bring the total to 100%.

[0062] Preparation method: completely consistent with Example 1.

[0063] This comparative example is a single-component microemulsion containing isooctyl fluoride, which has a narrow spectrum of control, effective only against annual broadleaf weeds, with poor control of perennial weeds, short residual effect, and requires an increased dosage to achieve a similar control effect. Compared with Example 1, this highlights the superiority of the compound formulation of the present invention.

[0064] Comparative Example 7: The raw material composition by mass percentage is as follows: 3% aminochloropyridine acid, 8% co-emulsifier, 20% compound solvent, 5% N,N-dimethyldecylamide, 15% ethylene glycol diacetate, 4% antifreeze, 1.5% stabilizer, 1.125% epoxidized soybean oil, 0.375% citric acid, and deionized water to bring the total to 100%.

[0065] Preparation method: completely consistent with Example 1.

[0066] This comparative example is a single-component microemulsion of aminopyridine acid, which has a narrow spectrum of control, poor efficacy against annual broadleaf weeds, and slow onset of action. Compared with Example 1, this further highlights the superiority of the compound formulation of the present invention.

[0067] Comparative Example 8: The raw material composition by mass percentage is as follows: 5% isooctyl fluoride, 3% aminopyridine acid, 15% compound emulsifier, 10% sodium dioctyl succinate sulfonate, 5% tristyrene-phenol polyoxyethylene ether phosphate triethanolamine salt, 8% co-emulsifier, 20% compound solvent, 5% N,N-dimethyldecylamide, 15% ethylene glycol diacetate, 4% antifreeze, 1.5% stabilizer, 1.5% epoxidized soybean oil, and deionized water to bring the total to 100%.

[0068] Preparation method: completely consistent with Example 1.

[0069] This comparative example uses a single stabilizer, epoxidized soybean oil, which can only inhibit the hydrolysis of isooctyl fluoride but cannot protect aminopyridine acid from photodegradation, resulting in a significant decrease in the efficacy of aminopyridine acid. Compared with Example 1, this highlights the synergistic protective effect of the compound stabilizer.

[0070] Comparative Example 9: The raw material composition by mass percentage is as follows: 5% isooctyl fluoride, 3% aminopyridine acid, 8% compound emulsifier, 5.33% sodium dioctyl succinate sulfonate, 2.67% tristyrene-phenylphenol polyoxyethylene ether phosphate triethanolamine salt, 8% co-emulsifier, 20% compound solvent, 5% N,N-dimethyldecylamide, 15% ethylene glycol diacetate, 4% antifreeze, 1.5% stabilizer, 1.125% epoxidized soybean oil, 0.375% citric acid, and deionized water to bring the total to 100%.

[0071] Preparation method: completely consistent with Example 1.

[0072] The amount of composite emulsifier used in this comparative example was too low, resulting in poor emulsification effect, unstable microemulsion system, and easy occurrence of layering and turbidity. Compared with Example 1, this highlights the rationality of the amount of composite emulsifier used in this invention.

[0073] Performance testing and results analysis: Comprehensive performance tests were conducted on the microemulsions prepared in Examples 1 to 8 and Comparative Examples 1 to 9. Commercially available isooctyl fluoride single microemulsions (Control 1) and commercially available aminopyridine single microemulsions (Control 2) were used as controls. Test items included appearance, microemulsion particle size, centrifugal stability, thermal storage stability, cold storage stability, dilution stability, efficacy, safety, and storage stability. The test methods strictly followed the relevant national standards for pesticide microemulsions (GB / T19378-2003, GB / T14825-2006). Specific test methods for each item are disclosed below to ensure the repeatability and verifiability of the testing process: (1) Appearance test: The visual observation method is adopted. Under natural light conditions at 25℃±2℃, observe the color, transparency and uniformity of the sample and record whether there are phenomena such as layering, crystallization, precipitation and turbidity. Judgment standard: no layering, no crystallization, no precipitation, and uniform transparent or semi-transparent liquid are qualified; otherwise, they are unqualified.

[0074] (2) Microemulsion particle size test: A laser particle size analyzer (model: Malvern Zetasizer NanoZS90) was used. The test temperature was 25℃±1℃. The sample was diluted with deionized water to a suitable concentration (to ensure the test signal was stable). After stirring evenly, the sample was injected into the test cell. Each sample was tested in parallel 3 times. The average value was taken as the microemulsion particle size. The judgment criteria were: the particle size ≤150nm was qualified, otherwise it was unqualified.

[0075] (3) Centrifugation stability test: A high-speed centrifuge (model: TG16-WS) was used. 10 mL of sample was placed in a centrifuge tube, the speed was adjusted to 3000 r / min, and centrifuged for 30 min. After centrifugation, the sample was taken out and visually observed to see if there was any layering or precipitation. Judgment criteria: No layering or precipitation is qualified, otherwise it is unqualified.

[0076] (4) Heat storage stability test: According to GB / T19378-2003, take 50mL of sample and place it in a brown sealed glass bottle, put it in a constant temperature incubator at 40℃±2℃, and keep it at a constant temperature for 14 days. During this period, observe the appearance changes of the sample every day. After the test, take it out and cool it to room temperature. Determine the content of effective components containing isooctyl fluoride and aminopyridine in the sample, and calculate the content retention rate (content after heat storage / initial content × 100%). Judgment criteria: if there is no obvious change in appearance and the content retention rate of effective components is ≥90%, it is qualified; otherwise, it is unqualified.

[0077] (5) Cold storage stability test: According to GB / T19378-2003, take 50mL of sample and place it in a brown sealed glass bottle, put it in a refrigerator at 0℃±2℃ and refrigerate for 7 days. During this period, observe the changes in the appearance of the sample every day. After the test, take it out and heat it to room temperature to observe whether there is layering, crystallization or precipitation. Judgment standard: no layering, no crystallization or precipitation is qualified, otherwise it is unqualified.

[0078] (6) Dilution stability test: Take 1 mL of sample and dilute it 100 times and 500 times with standard hard water (hardness is 342 mg / L, calculated as CaCO3). After stirring evenly, place it in a constant temperature environment of 25℃±2℃ and let it stand for 24 hours. Visually observe whether the diluted solution shows turbidity, layering, or precipitation. Judgment standard: no turbidity, no layering, and no precipitation are qualified; otherwise, they are unqualified.

[0079] (7) Efficacy test: Wheat fields were selected as experimental fields and divided into several plots (each plot is 15m²). 2 (3 replicates) Each test sample and control sample were sprayed separately. The spraying dosage was uniformly converted according to the content of the active ingredient (the examples and comparative examples were based on the concentration of the active ingredient in their respective formulas, and Control 1 and Control 2 were based on the commercially recommended dosage). The number of surviving weeds in each plot was investigated at 7, 14, 21 and 30 days after application, and the weed control rate was calculated (control rate = (number of weeds in the blank control area - number of weeds in the treatment area) / number of weeds in the blank control area × 100%). The test objects included target weeds such as Alopecurus aequalis, Artemisia annua, Galium aparine, Veronica persica and Portulaca oleracea.

[0080] (8) Safety test: Conducted simultaneously with efficacy test, observe the growth status of crops (wheat) in each treatment area, record whether there are symptoms of phytotoxicity such as yellowing, wilting, and deformity, calculate the phytotoxicity rate (phytotoxicity rate = number of phytotoxic plants / total number of plants × 100%), and the judgment criteria are: no phytotoxicity symptoms or phytotoxicity rate ≤ 5% is qualified, and phytotoxicity rate > 5% is unqualified.

[0081] (9) Storage stability test: Take 50 mL of sample and place it in a brown sealed glass bottle. Store it at 25℃±2℃ and in the dark for 12 months. At 6 months and 12 months of storage, determine the content of active ingredients containing isooctyl fluoride and aminopyridine in the sample. Calculate the content retention rate at 12 months. Judgment standard: the content retention rate ≥85% is qualified, otherwise it is unqualified.

[0082] All instruments and equipment used in the above tests were commercially available standard equipment, and all test reagents were of analytical grade. Variables were strictly controlled during the testing process to ensure the objectivity, accuracy, and repeatability of the test results. The specific test results are shown in Table 1 below. Table 1: Sample Name Appearance Microemulsion particle size nm Centrifugal stability thermal storage stability Cold storage stability Dilution stability (100x / 500x) Control efficacy rate (7d / 14d / 21d / 30d) Security Storage stability (content retention rate over 12 months) Example 1 pale yellow, transparent, homogeneous liquid 120 qualified Qualified, content retention rate 97% qualified Qualified / Qualified 88 / 92 / 90 / 86 No pesticide damage 92 Example 2 pale yellow, transparent, homogeneous liquid 110 qualified Qualified, content retention rate 96% qualified Qualified / Qualified 89 / 93 / 91 / 87 No pesticide damage 91 Example 3 pale yellow, transparent, homogeneous liquid 105 qualified Qualified, content retention rate 97% qualified Qualified / Qualified 88 / 92 / 91 / 86 No pesticide damage 93 Example 4 pale yellow, transparent, homogeneous liquid 115 qualified Qualified, content retention rate 96% qualified Qualified / Qualified 87 / 91 / 90 / 85 No pesticide damage 92 Example 5 pale yellow, transparent, homogeneous liquid 130 qualified Qualified, content retention rate 95% qualified Qualified / Qualified 92 / 95 / 94 / 90 No pesticide damage 90 Example 6 pale yellow, transparent, homogeneous liquid 95 qualified Qualified, content retention rate 97% qualified Qualified / Qualified 85 / 88 / 87 / 83 No pesticide damage 93 Example 7 pale yellow, transparent, homogeneous liquid 140 qualified Qualified, content retention rate 94% qualified Qualified / Qualified 93 / 96 / 95 / 91 No pesticide damage 89 Example 8 pale yellow, transparent, homogeneous liquid 100 qualified Qualified, content retention rate 96% qualified Qualified / Qualified 86 / 89 / 88 / 84 No pesticide damage 92 Comparative Example 1 Turbid liquid with a small amount of sediment 280 Unqualified Unqualified, content retention rate 82%. Unqualified Unqualified / Unqualified 70 / 72 / 68 / 62 No pesticide damage 78 Comparative Example 2 Turbid liquid with crystallization 250 qualified Unqualified, content retention rate 83%. Unqualified Unqualified / Unqualified 76 / 78 / 75 / 70 No pesticide damage 80 Comparative Example 3 Pale yellow transparent liquid, becomes cloudy after heat storage. 130 qualified Unqualified, content retention rate 78%. qualified Qualified / Qualified 88 / 85 / 78 / 65 No pesticide damage 75 Comparative Example 4 Non-uniform liquid, with stratification 360 Unqualified Unqualified, content retention rate 80%. Unqualified Unqualified / Unqualified 72 / 75 / 70 / 63 No pesticide damage 77 Comparative Example 5 Severe stratification, with a large amount of crystallization 450 Unqualified Unqualified, content retention rate 65% Unqualified Unqualified / Unqualified 48 / 45 / 40 / 35 There was pesticide damage; the yellowing rate was 35%. 60 Comparative Example 6 pale yellow transparent liquid 125 qualified Qualified, content retention rate 95% qualified Qualified / Qualified 82 / 78 / 57 / 42 No pesticide damage 90 Comparative Example 7 pale yellow transparent liquid 115 qualified Qualified, content retention rate 94% qualified Qualified / Qualified 48 / 55 / 60 / 62 No pesticide damage 89 Comparative Example 8 A pale yellow, transparent liquid that becomes cloudy after storage. 120 qualified Unqualified, content retention rate 81%. qualified Qualified / Qualified 88 / 82 / 75 / 68 No pesticide damage 76 Comparative Example 9 Turbid liquid, with layers 240 Unqualified Unqualified, content retention rate 85% Unqualified Unqualified / Qualified 74 / 76 / 73 / 68 No pesticide damage 82 Comparison 1 pale yellow transparent liquid 130 qualified Qualified, content retention rate 94% qualified Qualified / Qualified 83 / 79 / 60 / 45 No pesticide damage 88 Comparison 2 pale yellow transparent liquid 120 qualified Qualified, content retention rate 93% qualified Qualified / Qualified 50 / 60 / 65 / 68 No pesticide damage 87 Test Result Analysis: The microemulsions prepared in Examples 1 to 8 all met the required performance. They were all pale yellow, transparent, and homogeneous liquids without stratification, crystallization, or turbidity. The microemulsion particle size was between 95 and 140 nm, meeting the acceptable standards. Centrifugal stability, thermal stability, cold storage stability, and dilution stability all met the requirements. After 14 days of thermal storage, the retention rate of the active ingredient was above 94%. After 7 days of cold storage, there was no stratification or crystallization. After dilution 100 times and 500 times, there was no turbidity or precipitation. Regarding efficacy, the control rates in Examples 1 to 8 all reached above 85% after 7 days of application, above 88% after 14 days, and remained above 83% after 30 days, demonstrating a long duration of effectiveness significantly superior to the comparative and control samples.

[0083] In the safety test, Examples 1 to 8 showed no phytotoxicity and had no adverse effects on crop growth; in terms of storage stability, after 12 months of storage, the retention rate of the effective ingredients in Examples 1 to 8 was above 89%, indicating excellent stability.

[0084] Comparing the examples and comparative examples, it can be seen that: Comparative Example 1, due to the use of a single emulsifier, could not adapt to the lipophilic and hydrophilic properties of the two active ingredients, resulting in unsatisfactory stability and a significant decrease in efficacy; Comparative Example 2, due to the use of a single solvent, could not meet the solubility requirements of both active ingredients, resulting in crystallization and decreased stability and efficacy; Comparative Example 3, due to the lack of a compound stabilizer, had active ingredients that were easily hydrolyzed and photolyzed, leading to significant degradation in storage stability and efficacy; Comparative Example 4, due to the lack of a stepwise preparation and controlled-rate dropping process, resulted in insufficient emulsification and an unstable system; Comparative Example 5, due to excessive active ingredient dosage, could not form a stable microemulsion and caused phytotoxicity; Comparative Examples 6 and 7, being single-component formulations, had narrow spectrum of activity, short duration of action, and efficacy far lower than the examples; Comparative Example 8, due to the use of a single stabilizer, could not simultaneously protect both active ingredients, resulting in rapid efficacy degradation; Comparative Example 9, due to insufficient compound emulsifier dosage, had poor emulsification and an unstable system. Although Control 1 and Control 2, as commercially available single-component microemulsions, met the basic stability requirements, their efficacy, control rate, and duration of action were significantly lower than those of the embodiments of the present invention, further demonstrating the superiority of the technical solution of the present invention.

[0085] A comparison of the various embodiments shows that, after optimizing the dosage and addition method of the composite emulsifier in Example 2, the dilution stability was further improved; after adjusting the ratio of the composite emulsifier in Example 3, the microemulsion particle size was more uniform; after optimizing the composite solvent in Example 4, the problem of low-temperature crystallization was completely solved; after adjusting the dosage of active ingredients and adjuvants in Examples 5 to 8, the invention can be adapted to different weed densities and crop field requirements, and all performance characteristics remain qualified. This proves that the technical solution of the present invention has good adaptability and scalability, the preparation process is simple and controllable, and it can be industrialized on a large scale without problems of insufficient disclosure or inability to implement. The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention.

Claims

1. A microemulsion containing isooctyl fluoride and aminopyridine, comprising the following components by weight percentage: The mixture contains 1%-15% isooctyl fluoride, 1%-15% aminopyridine acid, 10%-22% compound emulsifier, 5%-11% co-emulsifier, 15%-28% compound solvent, 2%-6% antifreeze, 0.5%-2.5% stabilizer, and deionized water to bring the total to 100%. The compound emulsifier is composed of sodium dioctyl succinate sulfonate and tristyrene-phenylphenol polyoxyethylene ether phosphate triethanolamine salt. The compound solvent is composed of N,N-dimethyldecylamide and ethylene glycol diacetate. The stabilizer is composed of epoxidized soybean oil and citric acid. The co-emulsifier is dipropylene glycol methyl ether, and the antifreeze is glycerol.

2. The microemulsion according to claim 1, characterized in that, The stabilizer contains epoxidized soybean oil in a mass ratio of 3:1 to citric acid.

3. The microemulsion according to claim 1, characterized in that, The mass ratio of sodium dioctyl succinate sulfonate to tristyrene-phenylphenol polyoxyethylene ether phosphate triethanolamine salt in the composite emulsifier is 1:1, 2:1, 3:1 or 5:

1.

4. The microemulsion according to claim 1, characterized in that, The mass ratio of N,N-dimethyldecylamide to ethylene glycol diacetate in the composite solvent is 1:2, 1:3, or 1:

4.

5. The microemulsion according to claim 1, characterized in that, By weight percentage, it contains 5% isooctyl fluoride, 3% aminopyridine acid, 15%-18% compound emulsifier, 8% co-emulsifier, 20% compound solvent, 4% antifreeze, and 1.5% stabilizer.

6. The microemulsion according to claim 1, characterized in that, By weight percentage, it contains 3% isooctyl fluoride, 1% aminopyridine acid, 12% compound emulsifier, 6% co-emulsifier, 18% compound solvent, 3% antifreeze, and 1% stabilizer.

7. The microemulsion according to claim 1, characterized in that, By mass percentage, it contains 10%-15% isooctyl fluoride, 5%-15% aminopyridine acid, 20%-22% compound emulsifier, 10%-11% co-emulsifier, 22%-28% compound solvent, 5%-6% antifreeze, and 2%-2.5% stabilizer.

8. A method for preparing the microemulsion containing isooctyl fluoride and aminopyridine as described in any one of claims 1 to 7, comprising the following steps: Step 1, Preparation of oil phase: Add isooctyl fluoride to the composite solvent, place it in a constant temperature water bath at 55℃-65℃, stir at 280 rpm-350 rpm until completely dissolved, add the full amount or half amount of composite emulsifier, and continue stirring for 15 minutes-20 minutes to obtain a uniform oil phase; Step 2, Preparation of aqueous phase: Add aminopyridine acid, co-emulsifier, antifreeze and stabilizer to deionized water, place in a constant temperature water bath at 52℃-58℃, and stir at 220 rpm-280 rpm until completely dissolved to obtain a homogeneous aqueous phase; Step 3, Mixing and Emulsification: Add the aqueous phase dropwise to the oil phase at a rate of 0.8 mL / min to 1.5 mL / min. During the dropwise addition, maintain the oil phase temperature at 55℃ to 65℃ and the stirring speed at 350 rpm to 420 rpm. After the dropwise addition is complete, continue stirring for 18 to 30 minutes. If half of the composite emulsifier was added in Step 1, add the remaining half of the composite emulsifier at this time, adjust the stirring speed to 380 rpm to 450 rpm and continue stirring for 18 to 25 minutes. Cool to room temperature, filter to remove insoluble impurities, and obtain the microemulsion.

9. The preparation method according to claim 8, characterized in that, In step one, the constant temperature water bath for preparing the oil phase is 60℃-63℃, and the stirring speed for dissolving isooctyl fluoride is 300 rpm-350 rpm.

10. The preparation method according to claim 8, characterized in that, In step two, the constant temperature water bath for preparing the aqueous phase is 55℃-58℃, and the stirring speed for dissolving each component is 250 rpm-280 rpm.