A pyraclostrobin and propiconazole compound microemulsion, a preparation method and application thereof

Abstract

The present application relates to the technical field of pesticide preparation, in particular to a pyraclostrobin and propiconazole compound microemulsion, a preparation method and application thereof, which comprises, by mass percentage, pyraclostrobin 1-10%, propiconazole 5-20%, plant oil surfactant modified compound 5-15%, fatty alcohol EO / PO block copolymer 3-10%, essential oil alcohol ester nonionic mixture 1-6%, solvent 15-40%, defoaming agent 0.01-0.1%, and the balance is deionized water. By optimizing the product formula system, the compound microemulsion provided meets the needs of synergistic effect, wide temperature storage stability, high salt tank mixing compatibility, high leaf spread, and green low-foam aerial spraying adaptation, etc.

Description

Technical Field

[0001] This invention relates to the field of pesticide formulation technology, specifically to a microemulsion of pyraclostrobin and propiconazole, its preparation method, and its application. Background Technology

[0002] Large leaf spot and small leaf spot are prevalent fungal diseases in major corn-producing areas. The pathogens continuously infect leaves, damaging photosynthetic tissues, and severely affected fields can experience yield reductions of over 30%. Current control methods mostly use single agents of pyraclostrobin and propiconazole, or conventional compound formulations, but these have many problems such as resistance and poor formulation stability. For example, Chinese patent application (publication number CN106857540A) discloses a compound of fluopyram and triazoles such as propiconazole, with formulations and ratios targeting wheat scab and apple brown spot, but not suitable for corn with thick waxy leaves or aerial spraying scenarios. Chinese patent application (publication number CN109169673A) discloses a combination of fluopyram and cycloflufenoxam, targeting powdery mildew and gray mold, but completely unsuitable for corn leaf spot control.

[0003] Pyraclostrobin is a methoxyacrylate antibiotic with a broad spectrum of antibacterial activity but short-lived and prone to inducing resistance. Propiconazole belongs to the triazole class, with strong systemic activity, but long-term use alone reduces pathogen susceptibility. Conventional emulsifiable concentrates and suspensions are prone to crystallization and stratification at low temperatures. Commercially available pyraclostrobin... Propiconazole formulations have several problems: they often use nonylphenol emulsifiers and aromatic solvents, which easily crystallize and separate after cold or hot storage, resulting in a high effective decomposition rate; they easily break emulsions and flocculate when diluted with standard hard water or high-salt potassium dihydrogen phosphate solutions, and have poor stability when mixed with insecticides in tanks; the pesticide solution has a large contact angle on corn leaves, resulting in poor wetting and adhesion of leaf sheaths and lower leaves, and is easily washed away by rain; traditional formulations produce a large amount of foam, making them unsuitable for drone spraying, and the adjuvants are difficult to degrade, posing a risk of crop damage, and thus failing to meet practical application needs. Summary of the Invention

[0004] To address the aforementioned issues, this invention provides a microemulsion of pyraclostrobin and propiconazole. By optimizing the product formulation system, the provided microemulsion achieves synergistic effects, wide-temperature storage stability, compatibility with high-salt tank mixing, high foliar spreading, and suitability for green, low-foaming aerial spraying.

[0005] This invention provides a microemulsion of pyraclostrobin and propiconazole, comprising, by mass percentage: 1-10% pyraclostrobin technical grade, 5-20% propiconazole technical grade, 5-15% vegetable oil surfactant modified complex, 3-10% fatty alcohol EO / PO block copolymer, 1-6% essential oil alcohol ester nonionic mixture, 15-40% solvent, 0.01-0.1% defoamer, and the balance being deionized water.

[0006] During the development of the microemulsion described in this invention, due to the significant difference in solubility between pyraclostrobin and propiconazole, and the difficulty of conventional adjuvant systems simultaneously meeting the requirements for high and low temperature stability and high salt compatibility in tank mixing, the invention initially attempted to use emulsifiers such as triphenylethylphenol polyoxyethylene ether and nonylphenol polyoxyethylene ether. However, the resulting microemulsions crystallized during cold storage or precipitated crystals when diluted with hard water. The reason for this may be that the interfacial film formed by these conventional emulsifiers is not strong enough and is sensitive to high salt ions. Further introduction of castor oil or single block copolymers still could not solve the problems of stratification or poor wettability. In further investigation, it was unexpectedly discovered that when using a combination of vegetable oil surfactant-modified complexes, fatty alcohol EO / PO block copolymers, and essential oil alcohol ester nonionic mixtures, the microemulsion not only reduced the particle size to below 200 nm, but also maintained transparency and uniformity in the range of -18℃ to 60℃, and could withstand tank mixing with potassium dihydrogen phosphate and chlorantraniliprole·thiamethoxam suspension, while the contact angle was significantly reduced, making the provided product environmentally friendly, stable, and suitable for aerial spraying. The possible reasons are as follows: the modified complex of plant oil surfactants, the fatty alcohol EO / PO block copolymer, and the nonionic mixture of essential oil alcohol esters work together to effectively enhance the interfacial film strength. Through steric hindrance and temperature responsiveness, the interfacial film can maintain stability even in a high-concentration salt ion environment, effectively inhibiting the tight aggregation and crystallization of micelles at low temperatures, and resisting the compression of the electric double layer by electrolytes, thus simultaneously achieving low-temperature stability and high-salt tolerance. At the same time, the nonionic mixture of essential oil alcohol esters in the system significantly enhances the wetting and spreading ability of the drug solution on waxy leaves, ensuring the comprehensive effect of the microemulsion.

[0007] In one embodiment, the pyraclostrobin and propiconazole compound microemulsion comprises, by weight percentage: 5-8% pyraclostrobin technical grade and 10-15% propiconazole technical grade.

[0008] In one embodiment, the mass ratio of the pyraclostrobin technical material to the propiconazole technical material is 1-3:1-3.

[0009] In one embodiment, the amount of the vegetable oil surfactant-modified complex added is 8-12% by mass percentage.

[0010] In this invention, the vegetable oil surfactant modified complex is an amphiphilic complex obtained by using natural vegetable oils (such as castor oil, soybean oil, hydrogenated castor oil, etc.) as raw materials, introducing hydrophilic segments through alkoxylation (e.g., ethoxylation, propoxylation), and further undergoing esterification, sulfonation, or phosphoric acid esterification.

[0011] In one embodiment, the vegetable oil surfactant-modified complex is selected from at least one of castor oil polyoxyethylene ether, hydrogenated castor oil polyoxyethylene ether, soybean oil-based polyoxyethylene ether, and their sulfonate or phosphate derivatives.

[0012] In one embodiment, the type of the vegetable oil surfactant modified compound includes Qingyu SP-EC3508.

[0013] In one embodiment, the amount of the fatty alcohol EO / PO block copolymer added is 4-7% by mass percentage.

[0014] In this invention, the fatty alcohol EO / PO block copolymer is a C8-C 18 Block polyether nonionic surfactants are formed by the sequential or random addition of fatty alcohols to ethylene oxide (EO) and propylene oxide (PO). By adjusting the carbon chain length of the fatty alcohol, the EO / PO block ratio, and the sequence, products with different hydrophilic-lipophilic balance and salt resistance properties can be obtained.

[0015] In one embodiment, the fatty alcohol carbon chain of the fatty alcohol EO / PO block copolymer is C. 10 -C 16 The EO / PO block ratio is between 1:3 and 3:1.

[0016] In one embodiment, the fatty alcohol EO / PO block copolymer includes at least one of Nouryon Ethylan 992 or Ethylan 324.

[0017] In one embodiment, the amount of the nonionic mixture of essential oil alcohol esters added is 2-5% by mass percentage.

[0018] In this invention, the essential oil-based alcohol-ester nonionic mixture is a multifunctional penetration and spreading aid formulated with plant essential oil active ingredients (such as terpenes, terpene alcohols, phenols, etc.) as the core, and nonionic surfactants such as alcohols (such as fatty alcohols) and esters (such as fatty acid esters, citrate esters, etc.). The essential oil components endow it with excellent dynamic surface tension reduction capabilities and bioactivity, while the alcohol-ester components enhance dissolution and spreading.

[0019] In one embodiment, the essential oil alcohol ester nonionic mixture is an alcohol ester mixture based on rosin oil, orange peel oil, tea tree oil, or eucalyptus oil.

[0020] In one embodiment, the nonionic blend of essential oil alcohol esters includes the FTRT®TV-11.

[0021] Targeting the characteristics of corn leaves—thick waxy layer, upright leaf surface, and dense canopy—and the occurrence patterns of large and small leaf spot diseases (mostly starting from the lower leaves), this product incorporates FTRT®TV-11 from the formula. Its excellent surface tension enables rapid spreading, ensuring the solution covers the hard-to-reach leaf sheaths and undersides. Simultaneously, its rapid penetration through plant stomata significantly enhances the solution's penetration onto the leaf surface, promoting systemic absorption and protecting new leaves. This achieves a combination of precise application and high-efficiency protection, solving the problems of poor coverage and unstable efficacy of conventional pesticides on corn.

[0022] In one embodiment, the solvent comprises cyclohexanone and dipropylene glycol methyl ether.

[0023] In one embodiment, the mass ratio of cyclohexanone to dipropylene glycol methyl ether is 15-25:8-15.

[0024] Based on a specific emulsification system, this invention utilizes solvents including cyclohexanone and dipropylene glycol methyl ether to completely dissolve the two active pharmaceutical ingredients and prevent crystallization. Through this optimized emulsification system and solvent, the microemulsion maintains a uniform and transparent state even after long-term storage (heated or cold), exhibits low decomposition rates of the active ingredients, and demonstrates excellent physical and chemical stability. This results in a longer shelf life, reduces the likelihood of deterioration during storage and distribution, and ensures stable and reliable efficacy at the point of sale.

[0025] In one embodiment, the defoamer includes an organosilicone defoamer.

[0026] In one embodiment, the amount of defoamer added is 0.03-0.07% by mass percentage.

[0027] In one embodiment, the pyraclostrobin and propiconazole combined microemulsion satisfies at least one of the following conditions: (1) The particle size D of the microemulsion 90 ≤200nm; (2) The microemulsion maintains a uniform and transparent state within a temperature range of -18℃ to 60℃; (3) The microemulsion was diluted 10 to 20 times with 20 times potassium dihydrogen phosphate aqueous solution and allowed to stand for 24 hours without stratification or demulsification; (4) The microemulsion is mixed with 40% chlorantraniliprole·thiamethoxam suspension and potassium dihydrogen phosphate at a dilution ratio of 10:20:20~50 times. After standing for 24 hours, there is no flocculation or stratification.

[0028] Another aspect of the present invention provides a method for preparing a microemulsion of pyraclostrobin and propiconazole, comprising the following steps: The propiconazole technical and the fatty alcohol EO / PO block copolymer were preheated in a water bath. Add solvent to the stirred tank, start stirring, add pyraclostrobin technical material, and stir until completely dissolved; Add the propiconazole technical material heated in a water bath to the stirred tank and continue stirring until completely dissolved to obtain an oil phase mixture; Add the vegetable oil surfactant-modified complex, fatty alcohol EO / PO block copolymer and essential oil alcohol ester nonionic mixture to the oil phase mixture in sequence, and stir until completely dispersed; Add deionized water and defoamer to a stirred tank and continue stirring and dispersing for at least 30 minutes to obtain a microemulsion of pyraclostrobin and propiconazole.

[0029] In one embodiment, the water bath heating temperature is 40-60°C.

[0030] In one embodiment, the stirring speed is 200 to 500 rpm.

[0031] The third aspect of this invention provides the application of a microemulsion of pyraclostrobin and propiconazole in the control of fungal diseases in crops.

[0032] In one embodiment, the crop includes maize, and the fungal disease includes maize large leaf spot and / or maize small leaf spot.

[0033] In one embodiment, the method of using the pyraclostrobin and propiconazole compound microemulsion is as follows: the pyraclostrobin and propiconazole compound microemulsion is diluted with water 1000 to 3000 times and then applied by foliar spraying; or the pyraclostrobin and propiconazole compound microemulsion is mixed with potassium dihydrogen phosphate and chlorantraniliprole·thiamethoxam suspension and then applied by aerial spraying.

[0034] Beneficial effects 1. This invention provides a microemulsion of pyraclostrobin and propiconazole. By optimizing the product formulation system, the provided microemulsion meets the requirements of synergistic effect, wide temperature storage stability, high salt tank mixing compatibility, high foliar spreading, and green low foaming aerial spraying.

[0035] 2. When combined with vegetable oil surfactant-modified complexes, fatty alcohol EO / PO block copolymers, and essential oil alcohol ester nonionic mixtures, the microemulsion not only reduces the particle size to below 200nm, but also maintains transparency and uniformity in the range of -18℃ to 60℃. It can also withstand mixing with potassium dihydrogen phosphate and chlorantraniliprole suspension in tanks, while the contact angle is significantly reduced, making the provided product environmentally friendly, stable, and suitable for aerial spraying.

[0036] 3. This invention, through an optimized emulsification system and solvent, ensures that the microemulsion remains uniform and transparent after long-term storage (hot or cold storage), with a low decomposition rate of active ingredients and excellent physical and chemical stability, giving the product a longer shelf life and making it less prone to deterioration during storage and distribution, thus ensuring the stability and reliability of the final drug efficacy.

[0037] 4. The product provided by this invention has excellent spreadability and rapid absorption characteristics, avoiding prolonged retention and concentration of the liquid on the leaves, further reducing the risk of phytotoxicity such as burns and deformities to corn at the recommended dosage, making it safer to use.

[0038] 5. This invention uses a biodegradable vegetable oil surfactant modified complex to replace the traditional nonylphenol surfactant, ensuring excellent performance of the adjuvant while being completely biodegradable. It also eliminates highly toxic and irritating solvents such as benzene, making it gentle on corn plants, with low risk of phytotoxicity, and environmentally friendly. Furthermore, the process is simple and easy to control, making it suitable for large-scale industrial production. Attached Figure Description

[0039] Figure 1 The particle size distribution diagram of the microemulsion in Example 1 is shown (D90 is 183 nm).

[0040] Figure 2 This is an image showing the appearance of the microemulsion in Example 1 after cold storage (-18°C, 14 days).

[0041] Figure 3 The image shows the appearance of the microemulsion from Comparative Example 1 after being cold-stored (-6℃, 14 days) and then transferred to room temperature for 24 hours.

[0042] Figure 4 The image shows the appearance of Comparative Example 6 microemulsion after being cold-stored (-6℃, 14 days) and then transferred to room temperature for 24 hours.

[0043] Figure 5 This is a layered appearance diagram of the microemulsion in Comparative Example 2.

[0044] Figure 6 The image shows the appearance of Comparative Example 1 after being diluted 200 times with standard hard water and left to stand for 1 hour.

[0045] Figure 7 The image shows the appearance of Comparative Example 3 after being diluted 200 times with standard hard water and left to stand for 1 hour.

[0046] Figure 8 This is a comparison diagram of the contact angles of Example 1 (left) and Comparative Example 4 (right) on the test membrane.

[0047] Figure 9 The images show the appearance of Comparative Example 5 (left) and Example 2 (right) after being diluted 20 times with a 20-fold potassium dihydrogen phosphate aqueous solution and left to stand for 24 hours.

[0048] Figure 10 The images show the appearance of the product from Example 1 after being diluted 10 times (left), 15 times (middle), and 20 times (right) with a 20-fold potassium dihydrogen phosphate aqueous solution and left to stand for 24 hours.

[0049] Figure 11 The image shows the appearance of Example 1 after being mixed with 40% chlorantraniliprole·thiamethoxam SC and different amounts of potassium dihydrogen phosphate and left to stand for 24 hours. In the image, the left side corresponds to the addition of 12.5g of potassium dihydrogen phosphate, the middle side corresponds to the addition of 8.33g of potassium dihydrogen phosphate, and the right side corresponds to the addition of 5g of potassium dihydrogen phosphate.

[0050] Figure 12 Field efficacy test report of 19% pyraclostrobin·propiconazole microemulsion (Example 1) for controlling maize leaf spot.

[0051] Figure 13 This is a field efficacy test report on the control of maize leaf spot disease using 19% pyraclostrobin·propiconazole microemulsion (Example 1).

[0052] Figure 14 The figure shows the combined toxicity test results of pyraclostrobin and propiconazole in different ratios against maize leaf spot.

[0053] Figure 15 The figure shows the combined toxicity test results of pyraclostrobin and propiconazole in different ratios against maize leaf spot. Detailed Implementation

[0054] Example 1 This embodiment provides a microemulsion of pyraclostrobin and propiconazole, comprising, by mass percentage: 7% pyraclostrobin technical grade, 12% propiconazole technical grade, 10% vegetable oil surfactant modified complex (Qingyu SP-EC3508), 6% fatty alcohol EO / PO block copolymer (Nourion Ethylan 992), 4% essential oil alcohol ester nonionic mixture (Fangzhong FTRT® TV-11), 20% cyclohexanone, 10% dipropylene glycol methyl ether, 0.05% silicone defoamer (Momentive SAG 1572), and deionized water to 100%.

[0055] Another aspect of this embodiment provides a method for preparing a microemulsion of pyraclostrobin and propiconazole, comprising the following steps: The propiconazole technical and Ethylan 992 were pretreated by heating in a 50°C water bath; Add cyclohexanone and dipropylene glycol methyl ether to the stirred tank, start stirring (300 rpm), add pyraclostrobin technical material, and stir for 15 minutes until completely dissolved; Add propiconazole technical grade and continue stirring for 20 minutes until completely dissolved; Add SP-EC3508, Ethylan 992 and FTRT®TV-11 in sequence, and stir for 15 minutes until evenly dispersed; Add deionized water and organosilicon defoamer, and continue stirring for 30 minutes to obtain a transparent and homogeneous microemulsion of pyraclostrobin and propiconazole.

[0056] Example 2 This embodiment provides a microemulsion of pyraclostrobin and propiconazole, comprising, by mass percentage: 7% pyraclostrobin technical grade, 12% propiconazole technical grade, 8% vegetable oil surfactant modified complex (Qingyu SP-EC3508), 5% fatty alcohol EO / PO block copolymer (Noryon Ethylan 324), 3% essential oil alcohol ester nonionic mixture (Fangzhong FTRT® TV-11), 22% cyclohexanone, 10% dipropylene glycol methyl ether, 0.05% silicone defoamer (Momentive SAG 1572), and deionized water to 100%.

[0057] Another aspect of this embodiment provides a method for preparing a microemulsion of pyraclostrobin and propiconazole, which is the same as in Example 1.

[0058] Comparative Example 1 This comparative example provides a microemulsion of pyraclostrobin and propiconazole, comprising, by mass percentage: 7% pyraclostrobin technical, 12% propiconazole technical, 15% triphenylethylphenol polyoxyethylene ether (Kaiyuan KY601), 5% block polyether (Qingyu SP-3850), 20% solvent oil 200#, 10% cyclohexanone, 0.05% defoamer (Momentive SAG 1572), and deionized water to 100%.

[0059] This comparative example also provides a method for preparing a microemulsion of pyraclostrobin and propiconazole, comprising the following steps: The technical grade propiconazole was pretreated by heating it in a 50°C water bath. Add cyclohexanone and solvent 200# to the stirred tank, start stirring (300 rpm), add pyraclostrobin technical material, and stir for 15 minutes until completely dissolved; Add propiconazole technical grade and continue stirring for 20 minutes until completely dissolved; Add KY601 and SP-3850 in sequence, and stir for 15 minutes until evenly dispersed; Add deionized water and organosilicon defoamer, and continue stirring for 30 minutes to obtain a transparent and homogeneous microemulsion of pyraclostrobin and propiconazole.

[0060] Comparative Example 2 This comparative example provides a microemulsion of pyraclostrobin and propiconazole, comprising, by weight percentage: 7% pyraclostrobin technical, 12% propiconazole technical, 13% nonylphenol polyoxyethylene ether (Kaiyuan OP-10), 5% block polyether (Jierun 650L), 15% isophorone, 15% dimethylpropionamide, 0.05% defoamer (Momentive SAG 1572), and deionized water to 100%.

[0061] This comparative example also provides a method for preparing a microemulsion of pyraclostrobin and propiconazole, comprising the following steps: The technical grade propiconazole was pretreated by heating it in a 50°C water bath. Add isophorone and dimethylpropionamide to the stirred tank, start stirring (300 rpm), add pyraclostrobin technical material, and stir for 15 minutes until completely dissolved; Add propiconazole technical grade and continue stirring for 20 minutes until completely dissolved; Add OP-10 and 650L sequentially, and stir for 15 minutes until evenly dispersed; Add deionized water and organosilicon defoamer, and continue stirring for 30 minutes to obtain a transparent and homogeneous microemulsion of pyraclostrobin and propiconazole.

[0062] Comparative Example 3 This comparative example provides a microemulsion of pyraclostrobin and propiconazole, comprising, by weight percentage: 7% pyraclostrobin technical grade, 12% propiconazole technical grade, 13% nonylphenol polyoxyethylene ether (Kaiyuan OP-10), 5% calcium dodecylbenzenesulfonate (Kaiyuan 500#), 15% cyclohexanone, 15% dimethylpropionamide, 0.05% defoamer (Momentive SAG 1572), and deionized water to 100%.

[0063] This comparative example also provides a method for preparing a microemulsion of pyraclostrobin and propiconazole, comprising the following steps: The technical grade propiconazole was pretreated by heating it in a 50°C water bath. Add cyclohexanone and dimethylpropionamide to the stirred tank, start stirring (300 rpm), add pyraclostrobin technical material, and stir for 15 minutes until completely dissolved; Add propiconazole technical grade and continue stirring for 20 minutes until completely dissolved; Add OP-10 and 500# in sequence, and stir for 15 minutes until evenly dispersed; Add deionized water and organosilicon defoamer, and continue stirring for 30 minutes to obtain a transparent and homogeneous microemulsion of pyraclostrobin and propiconazole.

[0064] Comparative Example 4 This comparative example provides a microemulsion of pyraclostrobin and propiconazole, comprising, by mass percentage: 7% pyraclostrobin technical grade, 12% propiconazole technical grade, 15% castor oil ethylene oxide condensate (Kaiyuan EL20), 5% dodecylbenzenesulfonate ammonium salt (Kaiyuan ME02), 20% cyclohexanone, 10% N,N-dimethylacetamide, 0.05% defoamer (Momentive SAG 1572), and deionized water to 100%.

[0065] This comparative example also provides a method for preparing a microemulsion of pyraclostrobin and propiconazole, comprising the following steps: The technical grade propiconazole was pretreated by heating it in a 50°C water bath. Add cyclohexanone and N,N-dimethylacetamide to a stirred tank, start stirring (300 rpm), add pyraclostrobin technical grade, and stir for 15 minutes until completely dissolved; Add propiconazole technical grade and continue stirring for 20 minutes until completely dissolved; Add EL20 and ME02 in sequence, and stir for 15 minutes until evenly dispersed; Add deionized water and organosilicon defoamer, and continue stirring for 30 minutes to obtain a transparent and homogeneous microemulsion of pyraclostrobin and propiconazole.

[0066] Comparative Example 5 This comparative example provides a microemulsion of pyraclostrobin and propiconazole, comprising, by mass percentage: 7% pyraclostrobin technical grade, 12% propiconazole technical grade, 10% vegetable oil surfactant modified complex (Qingyu SP-EC3508), 20% cyclohexanone, 20% dipropylene glycol methyl ether, 0.05% defoamer (Momentive SAG 1572), and deionized water to 100%.

[0067] This comparative example also provides a method for preparing a microemulsion of pyraclostrobin and propiconazole, the same as in Example 1.

[0068] Comparative Example 6 This comparative example provides a microemulsion of pyraclostrobin and propiconazole, comprising, by weight percentage: 7% pyraclostrobin technical, 12% propiconazole technical, 8% EO / PO block copolymer (Noryon Ethylan 324), 10% cyclohexanone, 20% dipropylene glycol methyl ether, 0.05% defoamer (Momentive SAG 1572), and deionized water to 100%.

[0069] This comparative example also provides a method for preparing a microemulsion of pyraclostrobin and propiconazole, the same as in Example 1.

[0070] Performance testing 1. Physicochemical property testing Physicochemical properties of Examples 1-2 and Comparative Examples 1-6 were tested. The tests were conducted in accordance with the physicochemical index testing standard Q / SHYLSW 048-2025. The physicochemical indexes and some physicochemical test results of Example 1 are shown in Table 1.

[0071] (1) The particle size distribution of the product in Example 1 was determined by dynamic light scattering method. The results are shown in [reference]. Figure 1 And Table 2.

[0072] (2) The thermal storage stability was determined according to GB / T 19136-2021 (54℃±2℃, 14 days), and the results are shown in Table 2.

[0073] (3) Cold storage stability was determined according to GB / T 19137-2003 (-6℃, 14 days, and extended investigation at -18℃), and the results are shown in Table 2. Figure 2-4 .

[0074] (4) The persistent foaming property was determined according to GB / T 28137, and the results are shown in Table 2.

[0075] (5) Observe the product appearance; see the results below. Figure 5 And Table 2.

[0076] (6) Dilute 200 times with standard hard water: Dilute the products provided by Comparative Example 1 and Comparative Example 3 with standard hard water (total hardness 342 mg / L (calculated as CaCO3), containing Ca 2+ 137 mg / L, Mg 2+ (31 mg / L) Diluted 200 times, allowed to stand for 1 hour, and the product appearance was observed. See the results below. Figure 6 , Figure 7 .

[0077] (7) The microemulsions of Example 1 and Comparative Example 4 were diluted to the same concentration and dropped onto the surface of the test membrane. The contact angle was measured using a contact angle meter. The results are shown in [reference]. Figure 8 .

[0078] (8) The products of Comparative Example 5 and Example 2 were diluted 20 times with a 20-fold potassium dihydrogen phosphate aqueous solution (the mass ratio of potassium dihydrogen phosphate to tap water was 1:19, the same below), and left to stand for 24 hours. The appearance of the products was observed. The results are shown in [reference]. Figure 9 .

[0079] (9) The product of Example 1 was diluted with 20 times potassium dihydrogen phosphate aqueous solution to 10 times, 15 times, and 20 times respectively, and then allowed to stand for 24 hours. The appearance of the product was observed. The results are shown in [reference]. Figure 10 .

[0080] (10) Add 25g of the product from Example 1 and 12.5g of 40% chlorantraniliprole·thiamethoxam SC to a container, and add 12.5g, 8.33g, and 5g of potassium dihydrogen phosphate respectively. Dilute with tap water to 250g, mix, pour into a 100mL graduated cylinder, let stand for 24h, and observe the appearance of the product. See the results below. Figure 11 .

[0081] Table 1

[0082] Table 2

[0083] Note: “—” in Table 1 indicates that the corresponding performance was not measured.

[0084] Analyze the data in Tables 1 and 2 and Figure 1-11 The results show that: Examples 1 and 2 are transparent and uniform in appearance, and pass both hot and cold storage tests. They do not flocculate when diluted 200 times with standard hard water and have low persistent foaming properties. The D90 of Example 1 is only 183nm, indicating that the emulsion system has formed a stable nanoscale dispersion structure.

[0085] Comparative Example 1 used a traditional triphenylethylphenol polyoxyethylene ether system, which crystallized after cold storage and also crystallized after dilution with hard water; Comparative Example 2 showed layering; Comparative Example 3 showed crystallization after dilution with hard water; Comparative Example 4 showed acceptable stability but poor spreadability (see contact angle test); Comparative Examples 5 and 6, due to the lack of key auxiliary components, exhibited irreversible layering after high-salt dilution and turbidity after cold storage, respectively. These results demonstrate that the combined use of the three auxiliary agents in this invention is crucial for achieving high stability in the microemulsion.

[0086] pass Figure 9-11 It can be seen that: Example 1 maintained uniform transparency at all dilution factors. Figure 10 No flocculation or stratification occurred after mixing with potassium dihydrogen phosphate and chlorantraniliprole·thiamethoxam SC. Figure 11 Example 2: After dilution 20 times, the dispersion was good, with no crystallization or stratification. Figure 9 Right); Comparative Example 5 showed obvious stratification after being diluted 20 times ( Figure 9 (Left). This indicates that the microemulsion of the present invention has excellent stability in high-salt environments and under drum mixing conditions, making it suitable for aerial spraying operations.

[0087] 2. Field Trial 1: The field efficacy test report of 19% pyraclostrobin·propiconazole microemulsion (Example 1) for controlling maize leaf spot is available in the field. Figure 12 Field Trial 2: Field efficacy test report of 19% pyraclostrobin·propiconazole microemulsion (Example 1) for controlling maize leaf spot. (See attached report.) Figure 13Experimental results show that, under conditions of 150–225 g / ha of active ingredient, the control efficacy against maize leaf spot can reach over 85%, and the control efficacy against maize large leaf spot can reach over 82%, while being safe for maize growth and showing no phytotoxicity. Compared with conventional emulsifiable concentrate formulations, the microemulsion of this invention has comparable or slightly better control efficacy at the same active ingredient dosage, and also has advantages such as lower dosage, less environmental pollution, and suitability for aerial spraying.

[0088] 3. Co-toxicity coefficient: The combined toxicity test results of pyraclostrobin and propiconazole at different ratios against maize leaf spot are shown in [reference needed]. Figure 14 The results showed that: Propiconazole single agent against EC of maize small leaf spot 50 The EC50 of pyraclostrobin single agent was 1.1334 mg / L. 50 The concentration was 2.5434 mg / L, indicating that propiconazole alone was more toxic than pyraclostrobin alone. In the tested formulations, when the mass ratio of pyraclostrobin to propiconazole was 7:12, the EC50 of the compound combination was... 50 The lowest concentration was 1.0226 mg / L, while the highest co-toxicity coefficient (CTC) was 139.28, indicating the most significant synergistic effect. The CTC values ​​for all ratios were greater than or close to 120 (113.95 for the 1:3 ratio), showing an additive to synergistic effect; no antagonistic effect was observed. As the propiconazole ratio increased from 1:1 to 7:12, the toxicity of the combination gradually increased; when the propiconazole ratio was further increased to 1:2 and 1:3, the EC50... 50 There has been a slight rebound, but the degree of efficiency improvement has decreased.

[0089] The combined toxicity test results of pyraclostrobin and propiconazole at different ratios against maize leaf spot are shown in [reference]. Figure 15 The results showed that: Propiconazole as a single agent against EC50 of maize large leaf spot 50 The EC50 of pyraclostrobin single agent was 0.5092 mg / L. 50 The concentration was 1.0075 mg / L, indicating that propiconazole alone was more toxic than pyraclostrobin alone. Meanwhile, both single agents and their various combinations showed efficacy against EC50 of large leaf spot. 50 Values ​​were generally lower than those for EC5 for small spot disease. 50 The value indicates that the tested agent has stronger inhibitory activity against large leaf spot. In the tested formulation, the EC50 value of pyraclostrobin and propiconazole in a 1:1 ratio was the highest. 50 The lowest concentration was 0.4567 mg / L, while the highest CTC was 148.13, indicating the most significant synergistic effect. The CTC values ​​for all ratios were greater than 110, and no antagonistic effect was observed. The synergistic order was 1:1 > 2:1 > 7:12 ≈ 3:1 > 1:2 > 1:3, suggesting that both excessively high and low proportions of propiconazole would reduce the synergistic effect.

Claims

1. A microemulsion of pyraclostrobin and propiconazole, characterized in that, By weight percentage, it includes: 1-10% pyraclostrobin technical grade, 5-20% propiconazole technical grade, 5-15% vegetable oil surfactant modified complex, 3-10% fatty alcohol EO / PO block copolymer, 1-6% essential oil alcohol ester nonionic mixture, 15-40% solvent, 0.01-0.1% defoamer, and the balance is deionized water.

2. The microemulsion of pyraclostrobin and propiconazole according to claim 1, characterized in that, The mass ratio of pyraclostrobin technical grade to propiconazole technical grade is 1-3:1-3.

3. The pyraclostrobin and propiconazole compound microemulsion according to claim 1, characterized in that, The vegetable oil surfactant-modified complex is selected from at least one of castor oil polyoxyethylene ether, hydrogenated castor oil polyoxyethylene ether, soybean oil-based polyoxyethylene ether, and their sulfonate or phosphate derivatives.

4. The microemulsion of pyraclostrobin and propiconazole according to claim 1, characterized in that, The fatty alcohol carbon chain of the fatty alcohol EO / PO block copolymer is C. 10 -C 16 The EO / PO block ratio is between 1:3 and 3:

1.

5. The pyraclostrobin and propiconazole compound microemulsion according to claim 1, characterized in that, The fatty alcohol EO / PO block copolymer includes at least one of Nouryon Ethylan 992 or Ethylan 324.

6. The pyraclostrobin and propiconazole compound microemulsion according to claim 1, characterized in that, The essential oil alcohol ester nonionic mixture is an alcohol ester mixture based on rosin oil, orange peel oil, tea tree oil, or eucalyptus oil.

7. The pyraclostrobin and propiconazole compound microemulsion according to claim 1, characterized in that, The solvents include cyclohexanone and dipropylene glycol methyl ether.

8. The pyraclostrobin and propiconazole compound microemulsion according to claim 1, characterized in that, The defoamer includes silicone-based defoamers.

9. A method for preparing a microemulsion of pyraclostrobin and propiconazole according to any one of claims 1-8, characterized in that, Includes the following steps: The propiconazole technical and the fatty alcohol EO / PO block copolymer were preheated in a water bath. Add solvent to the stirred tank, start stirring, add pyraclostrobin technical material, and stir until completely dissolved; Add the propiconazole technical material heated in a water bath to a stirred tank and continue stirring until completely dissolved to obtain an oil phase mixture; Add the vegetable oil surfactant-modified complex, fatty alcohol EO / PO block copolymer and essential oil alcohol ester nonionic mixture to the oil phase mixture in sequence, and stir until completely dispersed; Add deionized water and defoamer to a stirred tank and continue stirring and dispersing for at least 30 minutes to obtain a microemulsion of pyraclostrobin and propiconazole.

10. The application of a microemulsion of pyraclostrobin and propiconazole according to any one of claims 1-8 in the control of fungal diseases in crops.

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