Microemulsions containing cyhalofop-butyl and metamifop and methods for their preparation

Abstract

The application provides a microemulsion containing cyhalofop-butyl and metamifop, which comprises, by mass percentage, 10-25% of active ingredients, 10-20% of solvents, 20-25% of emulsifiers, 5-10% of auxiliary surfactants, 2-5% of stabilizers, 0.5-2.5% of antifreezing agents, 1-3% of antievaporation agents, and the rest of water; the active ingredients are cyhalofop-butyl and metamifop; and the emulsifiers comprise low-molecular-weight emulsifiers with a molecular weight of less than 500 g / mol and high-molecular-weight emulsifiers with a molecular weight of more than 1500 g / mol. The microemulsion of the application has a particle size reaching the nanometer level, is suitable for use under high-temperature conditions, has high stability, and has good weeding effect.

Description

Technical Field

[0001] This invention belongs to the field of pesticides, specifically relating to microemulsions containing cyhalofop-butyl and oxazolidinyl and their preparation methods. Background Technology

[0002] Cyhalofop-butyl is a systemic herbicide of the oxyphenoxypropionic acid class, developed by Dow AgroSciences, and is highly safe for rice. It is absorbed through the leaves and leaf sheaths of plants, inhibiting acetyl-CoA carboxylase (ACCase), thereby affecting normal cell growth and division, ultimately leading to plant death. This herbicide is mainly used to control barnyard grass, Echinochloa crus-galli, Crataegus pinnatifida, and Eleusine indica, among other grassy weeds.

[0003] Oxaziclomefone is an aryloxyphenoxypropionate herbicide developed by the Korea Institute of Chemical Technology. It is another ACCase inhibitor that effectively inhibits the synthesis of fatty acids in plants, leading to weed death. Oxaziclomefone is mainly used to control annual grasses such as barnyard grass, goosegrass, and elm.

[0004] Rice is a major food crop in my country. With the expansion of direct-seeded rice cultivation, the herbicide resistance of grass weeds has increased dramatically. Although both oxadiazon and cyhalofop-butyl are ACCase inhibitors, they have different sites of action. Market feedback indicates that these two agents have a significant synergistic effect in weed control applications. However, under high summer temperatures, factors such as stomatal closure in weeds, thickening of the cuticle, and accelerated evaporation rate of pesticide droplets can lead to a significant decrease in efficacy.

[0005] Therefore, it is of great research significance to provide a herbicidal composition that maintains or further improves the efficacy of the combination of oxazolidinone and cyhalofop-butyl in high-temperature environments. Summary of the Invention

[0006] In order to overcome the shortcomings of the prior art, the present invention provides a microemulsion containing cyhalofop-butyl and oxazolidinyl, which has good stability and efficacy under high temperature conditions and expands the applicable scenarios.

[0007] A microemulsion containing cyhalofop-butyl and oxazolidinyl, comprising, by mass percentage, 10%–25% active ingredient, 10%–20% solvent, 20%–25% emulsifier, 5%–10% co-surfactant, 2%–5% stabilizer, 0.5%–2.5% antifreeze, 1%–3% antievaporator, and the balance being water;

[0008] The active ingredients are cyhalofop-butyl and oxazolidinyl;

[0009] The emulsifier comprises low molecular weight emulsifiers with a molecular weight <500 g / mol and high molecular weight emulsifiers with a molecular weight >1500 g / mol.

[0010] As an example, in the emulsifier, the mass ratio of low molecular weight emulsifier to high molecular weight emulsifier is 1:(1.5 to 7.5).

[0011] As an example, the low molecular weight emulsifier is selected from one or more combinations of sodium dodecylbenzenesulfonate, isotridecyl alcohol polyoxyethylene ether, sodium dioctyl sulfosuccinate, fatty alcohol polyoxyethylene ether, and alkyl glycosides.

[0012] The high molecular weight emulsifier has an HLB value greater than 11, and is preferably one or a combination of castor oil polyoxyethylene ether, propylene glycol block polyether, and tristyrene phenol polyoxyethylene ether.

[0013] As an example, the low molecular weight emulsifier is selected from one or a combination of two of sodium dodecylbenzenesulfonate, isotridecyl alcohol polyoxyethylene ether, and sodium dioctyl sulfosuccinate, and contains at least one anionic emulsifier;

[0014] The high molecular weight emulsifier is selected from one or a combination of two of styrene-phenylphenol polyoxyethylene ether, propylene glycol block polyether, and castor oil polyoxyethylene ether.

[0015] As an example, the co-surfactant is selected from one or more combinations of ethanol, isobutanol, isoamyl alcohol, isooctanol, dimethyl sulfoxide, dimethylacetamide, and N-methylpyrrolidone.

[0016] As an example, the stabilizer includes tristyrylphenol polyethylene glycol phosphate, and one or more combinations selected from sodium ethoxylated alkyl sulfate, sodium lauroyl sarcosinate, or sodium fatty alcohol polyoxyethylene ether sulfate.

[0017] As an example, the antifreeze is selected from one or more combinations of glycerol, propylene glycol, and ethylene glycol.

[0018] As an example, the anti-evaporation agent is selected from polyethylene glycol, glycerin, and Atplus. TM UEP-100, Hydravance TM 200, Synergen TM One or more combinations of operating systems.

[0019] As an example, the solvent is one or more selected from naphtha, cyclohexanone, xylene, isooctanol acetate, and ethylene glycol monobutyl ether acetate.

[0020] The present invention also provides a method for preparing a microemulsion containing cyhalofop-butyl and oxazolidinyl as described in any of the above contents, wherein the active ingredient, solvent, and co-surfactant are added to a stirred tank according to the formula, the temperature is raised to 30-40°C, and the mixture is stirred until the active ingredient is completely dissolved. Then, an emulsifier, stabilizer, antifreeze and anti-evaporation agent are added in sequence, and the mixture is stirred. Finally, the remaining water is added and the mixture is stirred again to obtain the microemulsion.

[0021] The present invention has the following advantages:

[0022] (1) This invention successfully prepared a microemulsion containing cyhalofop-butyl and oxazolidinyl by synergistic cooperation between the components and precise proportion of each component. The microemulsion obtained has a particle size at the nanoscale, which enriches the product types of rice herbicides and is also suitable for use under high temperature conditions.

[0023] (2) This invention combines a low molecular weight emulsifier (Mw < 500 g / mol) with a high molecular weight emulsifier (Mw > 1500 g / mol). The low molecular weight emulsifier promotes the formation of nano-sized oil droplets, while the high molecular weight emulsifier helps to delay the aggregation of diluted oil droplets. The two work synergistically to optimize the formation and stability of oil droplets. The prepared nanoemulsion, after 50-fold dilution, can maintain a particle size of less than 100 nm for at least 5 hours, making it particularly suitable for the formulation and application of aerial spraying agents.

[0024] (3) By adding specific stabilizers, the present invention successfully solved the problem of hydrolysis of oxazolidinyl in microemulsion formulations. The prepared nano-microemulsion emulsion has qualified stability, thermal storage stability and low temperature stability.

[0025] (4) This invention significantly improves the deposition rate after application and reduces the evaporation rate under high temperature conditions by reducing the surface tension, contact angle, and evaporation rate of the microemulsion containing cyhalofop-butyl and oxazolidinyl. At temperatures above 30°C, it can achieve a synergistic effect of more than 30%. Detailed Implementation

[0026] The technical solution of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, 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.

[0027] Anti-evaporation agents are selected from polyethylene glycol, glycerin, and Atplus. TM UEP-100 (Heda), Hydravance TM 200 (Grada), Synergen TM OS (Corian).

[0028] The ratio of emulsifier to solvent content is at least 1:1.

[0029] Example 1

[0030] Microemulsions containing cyhalofop-butyl and oxazolidinyl, by weight percentage, include:

[0031] Cyfluthrin 5%, Oxaloxacillin 5%, Cyclohexanone 10% (solvent), Naphtha 5% (solvent), Isooctyl alcohol 10% (co-surfactant), Sodium dioctyl sulfonate 3.2% (low molecular weight emulsifier), Sodium dodecylbenzenesulfonate 5.6% (low molecular weight emulsifier), Tristyrene-phenol polyoxyethylene ether 13.2% (high molecular weight emulsifier), Tristyrene-phenol polyethylene glycol phosphate 1% (stabilizer), Sodium fatty alcohol polyoxyethylene ether sulfate 2.5% (stabilizer), Ethylene glycol 1.5% (antifreeze), Atplus TM UEP-100 2% (anti-evaporation agent), the balance is tap water.

[0032] The preparation method is as follows:

[0033] Solvent, co-surfactant, cyhalofop-butyl technical grade, and oxazolidinyl technical grade are added to a stirred tank in proportion. The temperature is raised to 30-40°C, and the mixture is stirred until the active ingredients (cyhalofop-butyl technical grade and oxazolidinyl technical grade) are completely dissolved. Then, emulsifier, stabilizer, antifreeze agent, and anti-evaporation agent are added in sequence, and the mixture is stirred for 30 minutes. Finally, the remaining water is added, and the mixture is stirred for another 30 minutes to obtain a microemulsion containing cyhalofop-butyl and oxazolidinyl.

[0034] Examples 2 to 4, and Comparative Examples 1 to 4, were prepared according to the method steps of Example 1.

[0035] Example 2

[0036] Microemulsions containing cyhalofop-butyl and oxazolidinyl, by weight percentage, include:

[0037] The formula contains: 10% cyhalofop-butyl, 10% oxazolidinyl sulfadiazine, 10% isooctyl acetate (solvent), 5% xylene (solvent), 5% ethylene glycol mono-n-butyl ether acetate (solvent), 8% butanol (co-surfactant), 2.2% sodium dodecylbenzenesulfonate (low molecular weight emulsifier), 4% isotridecyl alcohol polyoxyethylene ether (low molecular weight emulsifier), 15.8% tristyrene phenol polyoxyethylene ether (high molecular weight emulsifier), 1.5% tristyrene phenol polyethylene glycol phosphate (stabilizer), 3% sodium fatty alcohol polyoxyethylene ether sulfate (stabilizer), 2.5% propylene glycol (antifreeze agent), 3% glycerin (anti-evaporation agent), and the balance being tap water.

[0038] Example 3

[0039] Microemulsions containing cyhalofop-butyl and oxazolidinyl, by weight percentage, include:

[0040] The formula consists of: 15% cyhalofop-butyl, 10% oxazolidinyl sulfadiazine, 10% cyclohexanone (solvent), 10% xylene (solvent), 5% ethanol (co-surfactant), 5% isooctanol (co-surfactant), 7.5% sodium dioctyl sulfonate succinate (low molecular weight emulsifier), 8.75% tristyrene-phenol polyoxyethylene ether (high molecular weight emulsifier), 8.75% castor oil polyoxyethylene ether (high molecular weight emulsifier), 1% tristyrene-phenol polyethylene glycol phosphate (stabilizer), 2% sodium fatty alcohol polyoxyethylene ether sulfate (stabilizer), 1.5% ethylene glycol (antifreeze agent), 2.5% polyethylene glycol (PEG-200) (anti-evaporation agent), and the balance being tap water.

[0041] Example 4

[0042] Microemulsions containing cyhalofop-butyl and oxazolidinyl, by weight percentage, include:

[0043] Cyhalofop-butyl 10%, oxazolidinyl 15%, cyclohexanone 10% (solvent), ethylene glycol monobutyl ether acetate 10% (solvent), ethanol 5% (co-surfactant), dimethyl sulfoxide 5% (co-surfactant), sodium dodecylbenzenesulfonate 5% (low molecular weight emulsifier), propylene glycol block polyether L64 (high molecular weight emulsifier) ​​2.5%, tristyrene-phenol polyoxyethylene ether 15% (high molecular weight emulsifier), tristyrene-phenol polyethylene glycol phosphate 1.5% (stabilizer), fatty alcohol polyoxyethylene ether sodium sulfate 3% (stabilizer), ethylene glycol 1.5% (antifreeze), Hydravance TM 200 (anti-evaporation agent) 2%, the remainder is tap water.

[0044] Comparative Example 1

[0045] Microemulsions containing cyhalofop-butyl and oxazolidinyl, by weight percentage, include:

[0046] Cyhalofop-butyl 5%, oxazolidinyl chlorpyrifos 5%, cyclohexanone 10% (solvent), naphtha 5% (solvent), isooctanol 10% (co-surfactant), propylene glycol block polyether L64 11% (high molecular weight emulsifier), tristyrene-phenol polyoxyethylene ether 11% (high molecular weight emulsifier), tristyrene-phenol polyethylene glycol phosphate 1% (stabilizer), fatty alcohol polyoxyethylene ether sodium sulfate 2.5% (stabilizer), ethylene glycol 1.5% (antifreeze), Atplus TM UEP-100 2% (anti-evaporation agent), the balance is tap water.

[0047] Comparative Example 1 lacks low molecular weight emulsifiers.

[0048] Comparative Example 2

[0049] Microemulsions containing cyhalofop-butyl and oxazolidinyl, by weight percentage, include:

[0050] Cyfluthrin 5%, Oxaloxacillin 5%, Cyclohexanone 10% (solvent), Naphtha 5% (solvent), Isooctyl alcohol 10% (co-surfactant), Sodium dodecylbenzenesulfonate 4.4% (low molecular weight emulsifier), Sodium dioctyl sulfosuccinate 4.4% (low molecular weight emulsifier), Alkyl glycoside 13.2% (low molecular weight emulsifier), Tristyrene-phenol polyethylene glycol phosphate 1% (stabilizer), Sodium fatty alcohol polyoxyethylene ether sulfate 2.5% (stabilizer), Ethylene glycol 1.5% (antifreeze), Atplus TM UEP-100 2% (anti-evaporation agent), the balance is tap water.

[0051] Comparative Example 2 lacks high molecular weight emulsifiers.

[0052] Comparative Example 3

[0053] Cyhalofop-butyl 5%, oxazolidinyl chlorpyrifos 5%, cyclohexanone 10% (solvent), naphtha 5% (solvent), isooctanol 10% (co-surfactant), sodium dioctyl sulfonate 1.65% (low molecular weight emulsifier), sodium dodecylbenzene sulfonate 3.45% (low molecular weight emulsifier), tristyrene-phenol polyoxyethylene ether 9.9% (high molecular weight emulsifier), tristyrene-phenol polyethylene glycol phosphate 1% (stabilizer), sodium fatty alcohol polyoxyethylene ether sulfate 2.5% (stabilizer), ethylene glycol 1.5% (antifreeze), Atplus TM UEP-100 2% (anti-evaporation agent), the balance is tap water.

[0054] The emulsifier content in Comparative Example 3 is not within the range of 20% to 25% of that in this invention.

[0055] Comparative Example 4

[0056] Microemulsions containing cyhalofop-butyl and oxazolidinyl, by weight percentage, include:

[0057] Cyhalofop-butyl 5%, oxazolidinyl chlorpyrifos 5%, cyclohexanone 10% (solvent), naphtha 5% (solvent), isooctanol 10% (co-surfactant), sodium dioctyl sulfonate 2.2% (low molecular weight emulsifier), sodium dodecylbenzene sulfonate 4.6% (low molecular weight emulsifier), tristyrene-phenol polyoxyethylene ether 13.2% (high molecular weight emulsifier), tristyrene-phenol polyethylene glycol phosphate 0.5% (stabilizer), sodium fatty alcohol polyoxyethylene ether sulfate 0.5% (stabilizer), ethylene glycol 1.5% (antifreeze), Atplus TM UEP-100 2% (anti-evaporation agent), the balance is tap water.

[0058] The stabilizer content in Comparative Example 4 is not within the range of 2% to 5% of that in this invention.

[0059] Compare with Example 1

[0060] Commercially available 10% oxadiazon EC products (5% cyhalofop-butyl and 5% oxadiazon). ， Non-nanoparticle size.

[0061] Compare with Example 2

[0062] Commercially available 20% oxadiazon EC products (10% cyhalofop-butyl and 10% oxadiazon). ， Non-nanoparticle size.

[0063] Compare with Example 3

[0064] Commercially available 25% oxazolidinone EC products (15% cyhalofop-butyl and 10% oxazolidinone) are non-nano-sized.

[0065] Experimental Example 1: Study on Physicochemical Properties and Stability

[0066] Particle size test: Dynamic light scattering method was used. After diluting the sample, it was allowed to stand at room temperature for 5 hours (50 times dilution for aerial spraying, 200 times dilution for conventional spraying). Then, 1 μL of sample was slowly added to the sample cell, avoiding the generation of air bubbles. Each sample was measured 5 times, and the particle size (Z-mean particle size) was the average of the five measurements.

[0067] Low-temperature stability test: Place 20 mL of sample in an ampoule and store at 0±2℃ for 7 days. Remove the sample and allow it to return to room temperature, then observe its state changes.

[0068] Thermal stability test: 20 mL of sample was placed in an ampoule and stored at 54±2℃ for 14 days. The sample was then removed and allowed to return to room temperature. Its condition was observed, and the degradation rate of oxazolidinyl was detected by high performance liquid chromatography.

[0069] Evaporation test: The temperature and humidity of the constant temperature and humidity chamber were set to 35℃ and 60% to simulate a summer environment. 10 mL of sample was taken and added to the surface of the *Eleusine indica* leaves using a pipette, and the initial weight was recorded. After placing the leaves in the constant temperature and humidity chamber for 30 minutes, the final weight was recorded. The evaporation rate (%) was calculated as (initial weight - final weight) / initial weight.

[0070] The microemulsions of Examples 1-4, Comparative Examples 1-4, and Control Examples 1-3 were all pale yellow transparent liquids that could be rapidly dispersed in water as a transparent and uniform O / W emulsion upon dilution. Furthermore, the particle size, low-temperature stability, and thermal storage stability of these microemulsions were investigated, and the results are shown in Table 1.

[0071] Table 1

[0072]

[0073]

[0074] As can be seen from Table 1, the nano-microemulsions provided in Examples 1-4 of the present invention can maintain the nano-particle size range for a long time after dilution in both conventional application and aerial spraying, which is significantly better than commercially available emulsifiable concentrate products (Comparative Examples 1 to 3).

[0075] Comparative Example 1 (lacking low molecular weight emulsifier) ​​was milky white after dilution, indicating that relying solely on slow-moving high molecular weight emulsifiers could not quickly reach the oil-water interface, resulting in the inability to effectively form small-diameter oil droplets.

[0076] Comparative Example 2 (lacking high molecular weight emulsifier) ​​appeared transparent with a bluish tint after dilution, but quickly turned milky white, indicating that low molecular weight emulsifier alone could not maintain the stability of the oil droplet interface for a long time, leading to oil droplet aggregation and increased particle size.

[0077] Comparative Example 3 (emulsifier content not in the range of 20% to 25%) was transparent with a bluish tint after dilution, but gradually became translucent during standing. This indicates that the combination of high molecular weight emulsifier and low molecular weight emulsifier cannot maintain the stability of the interface for a long time when the content is insufficient, resulting in oil droplet aggregation.

[0078] Comparative Example 4 (stabilizer content not within the range of 2% to 5%) changed color from light yellow to dark red after 14 days of heat storage. The test results showed that the decomposition rate of oxazolidinium seriously exceeded the standard, indicating that when the amount of stabilizer added is insufficient, it cannot effectively prevent the hydrolysis reaction of oxazolidinium at the oil-water interface, and therefore cannot be used.

[0079] Test Example 2: Efficacy Test

[0080] Field control efficacy tests of weeds in paddy fields were conducted using Examples 1-4, Comparative Examples 1-3, and Control Examples 1-3, respectively.

[0081] During the testing period, the temperature ranged from 28 to 37°C. The dosage of the drug for each sample was set according to the total active ingredient (g / mu) as follows: the dosage for Examples 1-4 was 30 g / mu and 40 g / mu, and the dosage for Comparative Examples 1-3 was 40 g / mu. The control group was the commercially available product oxazolidinone EC, and the dosage for Comparative Examples 1-3 was 40 g / mu.

[0082] The experiment consisted of 11 treatment groups, 3 control groups, and 1 blank control group, with 3 replicates per group, totaling 45 plots arranged in a randomized block design. Barnyardgrass, crabgrass, and sedge were used as the test weeds. The control efficacy was recorded 14 and 28 days after application. The results are shown in Table 2 (control efficacy of formulations with cyhalofop-butyl and oxadiazon as active ingredients against weeds 14 days after application) and Table 3 (control efficacy of formulations with cyhalofop-butyl and oxadiazon as active ingredients against weeds 28 days after application).

[0083] Control efficacy = (Number of weeds in the control area - Number of weeds in the treatment area) / Number of weeds in the control area * 100%

[0084] Table 2

[0085]

[0086] Table 3

[0087]

[0088]

[0089] According to the results in Tables 2 and 3:

[0090] The microemulsions provided by this invention (Examples 1 to 4) demonstrated significantly superior control efficacy against weeds such as barnyardgrass, crabgrass, and millet in high-temperature summer conditions within 14 and 28 days after application. Even at a dosage of 30 g / mu of total active ingredient, the microemulsions were still more effective than commercially available emulsifiable concentrates (Comparative Examples 1 to 3) at a dosage of 40 g / mu of total active ingredient, indicating that the reduction in nanoparticle size and evaporation rate jointly enhanced the efficacy. Among them, Example 1 showed the best control efficacy at a dosage of 40 g / mu of total active ingredient. Fourteen days after application, the control efficacy against barnyardgrass, crabgrass, barnyardgrass, and annual grass weeds reached 89.63%, 90.12%, 83.32%, and 87.69%, respectively; twenty-eight days after application, the control efficacy further increased to 92.33%, 95.8%, 89.49%, and 92.54%. In contrast, Comparative Example 1 (lacking low molecular weight emulsifier), Comparative Example 2 (lacking high molecular weight emulsifier), and Comparative Example 3 (emulsifier content not within the scope of this invention) showed significantly lower control efficacy at 14 and 28 days at a total active ingredient dosage of 40 g / mu compared to Examples 1 to 4 (total active ingredient 40 g / mu), but similar to the control efficacy of Examples 1 to 4 at a dosage of 30 g / mu. Furthermore, Comparative Example 2 had a similar particle size to Control Example 1, but a slower evaporation rate. At a dosage of 40 g / mu of total active ingredient, its efficacy was significantly better than that of Control Example 1, further demonstrating the combined effect of particle size and evaporation rate on the final control effect.

[0091] In summary, the microemulsion provided by this invention has good dispersibility, small particle size, excellent storage stability and anti-evaporation properties, and is highly effective against weeds such as barnyardgrass, crabgrass, and sedge, with rapid onset of action, making it suitable for weed control in paddy fields under high-temperature conditions in summer.

Claims

1. A microemulsion containing cyhalofop-butyl and oxazolidinyl, comprising, by mass percentage, 10%–25% active ingredient, 10%–20% solvent, 20%–25% emulsifier, 5%–10% co-surfactant, 2%–5% stabilizer, 0.5%–2.5% antifreeze, 1%–3% antievaporator, with the balance being water; The active ingredients are cyhalofop-butyl and oxazolidinyl; The emulsifier comprises low molecular weight emulsifiers with a molecular weight <500 g / mol and high molecular weight emulsifiers with a molecular weight >1500 g / mol; In the emulsifier, the mass ratio of low molecular weight emulsifier to high molecular weight emulsifier is 1:(1.5~7.5). The low molecular weight emulsifier is selected from one or a combination of two of sodium dodecylbenzenesulfonate, isotridecyl alcohol polyoxyethylene ether, and sodium dioctyl sulfosuccinate, and contains at least one anionic emulsifier. The high molecular weight emulsifier is selected from one or a combination of two of styrene-phenylphenol polyoxyethylene ether, propylene glycol block polyether, and castor oil polyoxyethylene ether.

2. The microemulsion containing cyhalofop-butyl and oxazolidinyl according to claim 1, characterized in that, The co-surfactant is selected from one or more combinations of ethanol, isobutanol, isoamyl alcohol, isooctanol, dimethyl sulfoxide, dimethylacetamide, and N-methylpyrrolidone.

3. The microemulsion containing cyhalofop-butyl and oxazolidinyl according to claim 1, characterized in that, The stabilizer includes tristyrene-phenylphenol polyethylene glycol phosphate, and one or more combinations selected from sodium ethoxylated alkyl sulfate, sodium lauroyl sarcosinate, or sodium fatty alcohol polyoxyethylene ether sulfate.

4. The microemulsion containing cyhalofop-butyl and oxazolidinyl according to claim 1, characterized in that, The antifreeze is selected from one or more combinations of glycerol, propylene glycol, and ethylene glycol.

5. The microemulsion containing cyhalofop-butyl and oxazolidinyl according to claim 1, characterized in that, The anti-evaporation agent is selected from one or more combinations of polyethylene glycol, glycerin, Atplus™ UEP-100, Hydravance™ 200, and Synergen™ OS.

6. The microemulsion containing cyhalofop-butyl and oxazolidinyl according to claim 1, characterized in that, The solvent is selected from one or more of naphtha, cyclohexanone, xylene, isooctanol acetate, and ethylene glycol monobutyl ether acetate.

7. The method for preparing the microemulsion containing cyhalofop-butyl and oxazolidinyl as described in any one of claims 1-6, characterized in that: Add the active ingredient, solvent, and co-surfactant to a stirred tank according to the formula, heat to 30-40°C, and stir until the active ingredient is completely dissolved. Then add the emulsifier, stabilizer, antifreeze, and anti-evaporation agent in sequence, stir, and finally add the remaining water and continue stirring to obtain the final product.

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