A biphasic herbicidal dispersible oil suspension and its preparation method

Abstract

This invention belongs to the field of agricultural chemistry and relates to a biphasic herbicidal dispersible oil suspension and its preparation method. The formulation consists of an oil phase A and a nano-aqueous phase B. Oil phase A contains a ternary compound herbicide of mesosulfuron-methyl, diflubenzuron, and clodinafop-propargyl, as well as safener A. Nano-aqueous phase B contains safener B, a hydrophilic co-solvent, and an aqueous phase adjuvant, ensuring that safener A is primarily distributed in the oil phase and safener B is primarily distributed in the aqueous phase, synergistically with a specific oil phase solvent, emulsifier, and polymer dispersion system. A pre-dispersion and sand milling process is used to obtain a biphasic fine-particle structure of oil droplets and nano-aqueous phase, maintaining good dilution and storage stability under high active ingredient loading conditions, while significantly reducing phytotoxicity to wheat and improving the control efficacy and duration of action against grasses and broadleaf weeds in wheat fields.

Description

Technical Field

[0001] This invention belongs to the field of agricultural chemistry, specifically relating to a biphasic herbicidal dispersible oil suspension and its preparation method. Background Technology

[0002] Wheat field weed communities are typically composed of a mixture of grasses and broadleaf weeds. Using herbicides with a single mechanism of action makes it difficult to achieve a balance in terms of control spectrum, resistance management, and residual effect. Therefore, ternary formulations of herbicides with different mechanisms of action, such as mesosulfuron-methyl, diflubenzuron, and clodinafop-propargyl, have become an effective technical approach for controlling major weeds such as jointed goatgrass, wild oats, wild wheatgrass, and shepherd's purse, while delaying the development of herbicide resistance. Correspondingly, oil-dispersible suspensions are widely used in the production of such formulations because they can increase the loading of active ingredients and improve wetting, spreading, and penetration properties on leaves.

[0003] However, preparing various high-load herbicides into traditional single-phase dispersible oil suspensions faces the following challenges: First, there is the challenge of physical stability. The coexistence of multiple herbicides with different physicochemical properties in a single oil phase can easily lead to excessively high local concentrations, crystal precipitation, or coarsening of particle size during storage due to differences in solubility and compatibility. This can cause formulation stratification, accelerated sedimentation, or abnormal viscosity, ultimately affecting its dilution stability and the uniformity of field application.

[0004] Second, the additive system becomes more complex. To stabilize multiple active ingredients simultaneously in a single phase, it is often necessary to increase the amount or types of emulsifiers and dispersants. This not only increases costs but also makes it difficult to maintain the oil droplet size at a small scale for a long time. Under stress conditions such as temperature changes or centrifugation, aggregation and oil-water separation can easily occur.

[0005] Third, there are issues with crop safety. Ternary compound formulations increase the risk of crop phytotoxicity. While this can be mitigated by adding safeners such as glyphosate or pyrazosulfuron-methyl, current technologies typically involve simply mixing the safener and herbicide in the same oil phase. This configuration restricts the spatial distribution and timing of action of the safener on crops, potentially leading to delayed or insufficient protective effects. Furthermore, the competition for dissolution and adsorption sites among multiple components within a single phase may further destabilize the system.

[0006] To overcome the limitations of single-phase systems, existing technologies attempt to construct composite systems with high water content, hoping to utilize the aqueous phase to share some of the functions. However, these attempts still face two major bottlenecks: first, it is difficult to stably control the particle size of the aqueous phase at the nanoscale, as coarsening of the aqueous phase can lead to flocculation at the two-phase interface, emulsification of the system, or phase separation after dilution; second, there is a lack of effective control over the distribution behavior of the safener between the two phases, and improper distribution can lead to solubilization imbalance in the oil phase or overload of the stabilizer in the aqueous phase, thereby simultaneously impairing the physical stability of the formulation and crop safety.

[0007] Therefore, there is an urgent need in the field for a formulation that can simultaneously achieve long-term stability of the biphasic structure, directional distribution of two types of safeners, and precise control of the particle size of the oil and aqueous phases in the context of high-load ternary herbicides, thereby comprehensively improving efficacy, safety and physical stability. Summary of the Invention

[0008] In response to the problems found in the background art, the present invention proposes a biphasic herbicidal dispersible oil suspension and its preparation method, aiming to solve the above problems.

[0009] To achieve the above objectives, the technical solution adopted by the present invention includes a biphasic herbicidal dispersible oil suspension, which, by weight percentage of the total formulation, is composed of an oil phase A and a nano-aqueous phase B; the oil phase A includes 1-5% mesosulfuron-methyl, 2-8% diflubenzuron, 5-15% clodinafop-propargyl, 1-4% safer A, 20-50% oil phase solvent, and 5-20% total of oil phase emulsifier and oil phase dispersant; the nano-aqueous phase B includes 1-4% safer B, 5-20% hydrophilic co-solvent, 15-40% water, and 1-10% total of aqueous phase emulsifier and polymeric dispersant; The total content of mesosulfuron-methyl, diflubenzuron and clodinafop-propargyl is 8-15%, the total content of safener A and safener B is 3-7%, at least 70% of the total mass of safener B is allocated to the nano-aqueous phase B, at least 80% of the total mass of safener A is allocated to the oil phase A, and the mass ratio of oil phase A to nano-aqueous phase B is 8:2-7:3.

[0010] Preferably, safer A is pyrazosulfuron-methyl and safer B is pyrazosulfuron-methyl.

[0011] Preferably, the mass ratio of mesosulfuron-methyl, diflubenzuron and clodinafop-propargyl in oil phase A is (0.5~1.5):(1.5~3.5):(5.0~10.0), and the mass ratio of safener A to the total amount of the three herbicides is 0.15~0.40.

[0012] Preferably, the oil phase solvent is selected from one or more combinations of methyl oleate, rapeseed oil methyl oleate, soybean oil methyl oleate, palm oil methyl oleate, isopropyl myristate and caprylic / capric diglyceride, and the oil phase emulsifier includes at least one of tristyrylphenol polyoxyethylene ether and calcium dodecylbenzenesulfonate.

[0013] Preferably, the oil phase dispersant comprises organic bentonite, and the mass ratio of oil phase emulsifier to oil phase dispersant is 1:1 to 1:3.

[0014] Preferably, the hydrophilic cosolvent is selected from one or more combinations of propylene glycol, glycerol, N-methylpyrrolidone and dipropylene glycol methyl ether.

[0015] Preferably, the aqueous emulsifier is a nonionic surfactant with an HLB value greater than 10, and the polymeric dispersant is an acrylic copolymer dispersant or a maleic anhydride copolymer dispersant; and the oil droplet volume distribution D50 of the suspending agent is 1.0~3.0μm and D90 is not greater than 5.0μm, and the D50 of the nano aqueous phase B is 50~500nm and D90 is not greater than 800nm.

[0016] The present invention also proposes a method for preparing the biphasic herbicidal dispersible oil suspension, comprising: S1. Add the oil phase solvent, oil phase emulsifier and oil phase dispersant to the premix tank and shear and disperse to form the oil phase base material; S2. Under shearing conditions, add diflubenzuron, mesosulfuron-methyl, clodinafop-propargyl and safer A sequentially to the oil phase base material, and continue shearing and homogenizing to obtain an oil phase slurry. S3. Prepare an aqueous phase separately by adding a hydrophilic co-solvent, an aqueous emulsifier, a polymeric dispersant, and a safety agent B to the water and then shearing and homogenizing to obtain a nano-aqueous phase B slurry. S4. Mix the oil phase slurry and the nano aqueous phase B slurry at a mass ratio of oil phase A to nano aqueous phase B of 8:2~7:3 and then perform two-stage sand milling. Control the outlet temperature to be no higher than 35℃ and the grinding chamber pressure to be no higher than 0.3MPa until the particle size D90 of the composition is no greater than 5.0μm and the particle size D90 of nano aqueous phase B is no greater than 800nm. S5. Cooling, degassing, wet sieving, filling and sealing.

[0017] Preferably, in step S1, the organic bentonite is first added to the oil phase solvent and pre-wetted at 2000~3500 rpm for 10~20 min before adding the oil phase emulsifier; in step S2, the order of adding the three herbicides is first diflubenzuron, then mesosulfuron-methyl, and then acetamiprid.

[0018] Preferably, in step S3, the mass ratio of the hydrophilic cosolvent to the aqueous emulsifier is 2:1 to 5:1, and the polymeric dispersant is 1 to 3% of the total mass of the nano-aqueous phase B. In step S4, the pressure of the sand mill grinding chamber is 0.2 to 0.3 MPa, and the cumulative grinding time is 40 to 60 min.

[0019] The beneficial effects of this invention include: (1) By constructing a two-phase structure in which oil phase A and nano-aqueous phase B coexist, and limiting the mass ratio of oil phase A to nano-aqueous phase B to 8:2~7:3, the herbicidal active ingredients and safener / water-based adjuvant are carried in separate phases, reducing the compatibility conflict of multiple active ingredients in a single phase, and reducing the probability of oil droplet aggregation, local concentration or sedimentation stratification during storage and transportation from the perspective of formulation structure.

[0020] (2) Two-stage sand milling is adopted and the grinding pressure, temperature and cumulative grinding time are limited so that the oil droplet particle size D90 is no greater than 5.0 μm and the nano water phase B particle size D90 is no greater than 800 nm, forming a controlled dual particle size distribution. This maintains the stability of the system interface under stress conditions such as hot storage, cold storage and centrifugation, and can still maintain a dispersible state after dilution, thereby improving the consistency of droplet composition and uniformity of pesticide coverage during field spraying.

[0021] (3) The phase-directed distribution of the two types of safeners is constrained, limiting that at least 70% of safener B is distributed in the nano-aqueous phase B and at least 80% of safener A is distributed in the oil phase A. This allows safener B to preferentially act on the crop leaves and surface tissues with the nano-aqueous phase, and safener A to enter the crop body with the oil droplets in the oil phase, forming a stepwise protective effect in time and space. This reduces the risk of phytotoxicity to wheat by the ternary compound herbicide and alleviates plant height inhibition.

[0022] (4) Within the range of the mass ratio and total content of the three herbicides, the synergistic effect of wetting and spreading and interfacial transfer of the biphasic system improves the deposition and systemic absorption process of mesosulfuron-methyl, diflubenzuron and clodinafop-propargyl on the leaves of weeds, so that the control efficacy against major weeds such as jointed goatgrass, wild oats, wild oats and shepherd's purse can remain at a high level in the 14-21 day stage, while the control efficacy decay is smaller than that of the single-phase system. Attached Figure Description

[0023] Figure 1 This is a process flow diagram for preparing the biphasic herbicidal dispersible oil suspension of the present invention. Detailed Implementation

[0024] The present invention will be further described below with reference to specific embodiments, but this is not intended to limit the scope of the invention. Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art.

[0025] I. Explanation of Raw Materials and Terminology The biphasic herbicide dispersible oil suspension of the present invention is a biphasic dispersible oil suspension system composed of an oil phase A and a nano-aqueous phase B. The oil phase A is an oily dispersion phase with a high herbicide loading, and the nano-aqueous phase B is a nano-sized aqueous dispersion phase containing a safener B. The two coexist in the formulation at a mass ratio of 8:2 to 7:3.

[0026] Composition of oil phase A: By percentage of total formulation mass, oil phase A comprises 1%–5% mesosulfuron-methyl, 2%–8% diflubenzuron, 5%–15% clodinafop-propargyl, 1%–4% safener A, 20%–50% oil phase solvent, and 5%–20% oil phase emulsifier and oil phase dispersant combined. The total content of mesosulfuron-methyl, diflubenzuron, and clodinafop-propargyl is 8%–15%. Within oil phase A, the mass ratio of mesosulfuron-methyl, diflubenzuron, and clodinafop-propargyl is (0.5–1.5):(1.5–3.5):(5.0–10.0), and the mass ratio of safener A to the total mass of the three herbicides is 0.15–0.40.

[0027] In one specific embodiment of the present invention, the oil phase solvent may be selected from one or more combinations of methyl oleate, rapeseed oil methyl oleate, soybean oil methyl oleate, palm oil methyl oleate, isopropyl myristate, and caprylic / capric diglyceride. The oil phase emulsifier includes at least one of tristyrene-phenylphenol polyoxyethylene ether and calcium dodecylbenzenesulfonate. The oil phase dispersant is preferably organobentonite, and the mass ratio of the oil phase emulsifier to the oil phase dispersant is 1:1 to 1:3.

[0028] The composition of the nano-aqueous phase B: Based on the total mass percentage of the formulation, the nano-aqueous phase B comprises 1%–4% safer B, 5%–20% hydrophilic co-solvent, 15%–40% water, and 1%–10% aqueous emulsifier and polymeric dispersant combined. In the entire formulation, the total content of safer A and safer B is 3%–7%. To achieve optimal phase distribution, at least 70% of the total mass of safer B is distributed in the nano-aqueous phase B, while at least 80% of the total mass of safer A is distributed in the oil phase A.

[0029] In one specific embodiment of the present invention, the hydrophilic co-solvent may be selected from one or more combinations of propylene glycol, glycerol, N-methylpyrrolidone, and dipropylene glycol methyl ether. The aqueous emulsifier is a nonionic surfactant with an HLB value greater than 10. The polymeric dispersant is an acrylic copolymer dispersant or a maleic anhydride copolymer dispersant.

[0030] In a preferred embodiment of the present invention, the safener A is pyrazosulfuron-methyl and the safener B is pyrazosulfuron-methyl.

[0031] Description of the main ingredients: (1) Methyl disulfuron, chemical name: 2-[3-(4,6-dimethoxypyrimidin-2-yl)ureasulfonyl]-4-methanesulfonamide methyl benzoate; molecular formula: C 17 H 21 N5O9S2, structural formula as follows: (2) Diflubenzuron, chemical name: 2',6'-difluoro-5-ethoxy-8-fluoro[1,2,4]triazole[1,5-c]pyrimidine-2-sulfonylaniline; molecular formula: C 12 H8F3N5O3S, structural formula as follows: ; (3) Propylene acetate, chemical name: (R)-2-4-[4-(5-chloro-3-fluoro-2-pyridinoxy)phenoxy]propionic acid propargyl ester; molecular formula: C 17 H 13 ClFNO4, the structural formula is as follows: ; (4) 1-Methylhexyl(5-chloro-8-quinolinoxy)acetic acid ester, chemical name: 1-methylhexyl(5-chloro-8-quinolinoxy)acetic acid ester; molecular formula: C 18 H 22 ClNO3, structural formula as follows: ; (5) Pyrazosulfuron, chemical name: (RS)-1-(2,4-dichlorophenyl)-5-methyl-2-pyrazoline-3,5-dicarboxylic acid diethyl ester; molecular formula: C 16 H 18 Cl2N2O4, the structural formula is as follows:

[0032] The biphasic herbicidal dispersible oil suspension prepared by this invention has an oil droplet volume distribution D50 of 1.0~3.0 μm and D90 of no more than 5.0 μm in oil phase A; and a nano aqueous phase B with a particle size D50 of 50~500 nm and D90 of no more than 800 nm.

[0033] The particle size can be determined using a laser particle size analyzer and / or a dynamic light scattering instrument. Before measurement, the sample is diluted with deionized water at a mass ratio of 1:20 to 1:50, and gently shaken before testing.

[0034] II. Preparation method of biphasic herbicidal dispersible oil suspension The biphasic herbicidal dispersible oil suspension of the present invention can be prepared by the following steps: S1. Preparation of the oil-phase base material: Add the oil-phase solvent to a premixing tank, turn on the high-speed shearing device and maintain a rotation speed of 2000~3500 rpm. Under shearing conditions, slowly add the oil-phase dispersant. As a preferred embodiment, when the oil-phase dispersant contains organobentonite, first add all of the organobentonite to the oil-phase solvent and pre-wet it at a rotation speed of 2000~3500 rpm for 10~20 minutes to allow the bentonite flakes to fully absorb oil and spread; then add the oil-phase emulsifier and continue shearing and dispersing for 5~10 minutes to obtain a uniform oil-phase base material.

[0035] S2. Preparation of the oil phase slurry: Maintaining shear conditions, add diflubenzuron, mesosulfuron-methyl, and clodinafop-propargyl sequentially to the oil phase base material obtained in step S1. After each herbicide is added, shear for 5-8 minutes to ensure sufficient dispersion. Then add safener A, and continue homogenization for 10-15 minutes under the same shear conditions to ensure thorough mixing and dispersion of the components, thus obtaining the oil phase slurry.

[0036] S3. Preparation of Nano Aqueous Phase B Slurry: In another aqueous premixing tank, metered water is added, and a high-speed shearing device is started, maintaining a rotation speed of 2500~4000 rpm. A hydrophilic co-solvent, aqueous emulsifier, polymeric dispersant, and safener B are added sequentially to the water, and the mixture is continuously sheared and homogenized for 15~25 minutes to obtain the nano aqueous phase B slurry. Preferably, the mass ratio of the hydrophilic co-solvent to the aqueous emulsifier is controlled to be 2:1~5:1, and the amount of polymeric dispersant added is 1%~3% of the total mass of the nano aqueous phase B.

[0037] S4. Two-phase mixing and milling: The oil phase slurry obtained in step S2 and the nano-aqueous phase B slurry obtained in step S3 are added to a mixing tank at a mass ratio of 8:2 to 7:3. The mixture is first premixed at low speed, then sheared at 1500 to 2500 rpm to obtain a two-phase coarse dispersion system. Subsequently, this system is fed into a two-stage mill for milling. During milling, the outlet temperature is controlled to be no higher than 35°C, the grinding chamber pressure is controlled to be no higher than 0.3 MPa (preferably 0.2 to 0.3 MPa), and the cumulative milling time is 40 to 60 minutes until the final product meets the following requirements: the oil droplet particle size D90 of the composition is no greater than 5.0 μm, and the particle size D90 of the nano-aqueous phase B is no greater than 800 nm.

[0038] S5. Post-processing: Cool the output material after sand milling in step S4 to reduce the system temperature to 25-30℃. Then, perform degassing treatment for 10-20 minutes, filter through an 80-120 mesh wet sieve, and finally fill and seal to obtain the finished biphasic herbicidal dispersible oil suspension.

[0039] III. Examples The present invention will be specifically described below through embodiments, but the scope of the present invention is not limited to these embodiments.

[0040] Example 1 The biphasic herbicidal oil-dispersible suspension of this embodiment comprises the following components by weight percentage of the total formulation: Oil phase A: 1.5% mesosulfuron-methyl, 2.5% diflubenzuron, 6.0% clodinafop-propargyl, 2.0% safener A (pyrazosulfuron-methyl), 45.0% oil phase solvent (methyl oleate), 5.0% oil phase emulsifier, and 8.0% oil phase dispersant (organo-bentonite). Nano-aqueous phase B: 2.5% safener B (pyrazosulfuron-methyl), 6.0% hydrophilic co-solvent, 18.5% water, 1.5% aqueous phase emulsifier, and 1.5% polymeric dispersant (acrylic acid copolymer).

[0041] In the oil phase A, the mass ratio of mesosulfuron-methyl, diflubenzuron, and clodinafop-propargyl is 1.5:2.5:6.0; the mass ratio of safener A to the total mass of the three herbicides is 0.20; the mass ratio of oil phase emulsifier to oil phase dispersant is 1:1.6; the mass ratio of hydrophilic cosolvent to aqueous phase emulsifier is 4:1; and the mass ratio of oil phase A to nano-aqueous phase B is 7:3.

[0042] The biphasic herbicidal dispersible oil suspension is prepared by the following steps: S1: Add the oil phase solvent to a premix tank, and slowly add the oil phase dispersant (organo-bentonite) at a shear speed of 2500 rpm, pre-wetting for 15 minutes. Then add the oil phase emulsifier (a compound of tristyrylphenol polyoxyethylene ether and calcium dodecylbenzenesulfonate), and continue shear dispersion for 8 minutes to obtain the oil phase base material.

[0043] S2: Maintaining shear conditions, add diflubenzuron, mesosulfuron-methyl, and clodinafop-propargyl sequentially to the oil phase base material, and shear disperse each component for 7 minutes after addition. Finally, add the safener A (clodinafop-propargyl) and continue homogenization for 12 minutes to obtain the oil phase slurry.

[0044] S3: In another container, add water, and at a shear speed of 3000 rpm, add the hydrophilic co-solvent (a mixture of propylene glycol and N-methylpyrrolidone), the aqueous emulsifier (Tween-80), the polymeric dispersant, and the safener B (pyrazole oxychloride). Shear homogenize for 20 minutes to obtain nano-aqueous phase B slurry.

[0045] S4: The oil phase slurry and the nano-aqueous phase B slurry are mixed at a mass ratio of 8:2 and ground in a two-stage sand mill. The grinding pressure is controlled at 0.25 MPa, the outlet temperature is not higher than 35℃, and the cumulative grinding time is 50 minutes.

[0046] S5: Cool the product after sand milling to 28°C, degas for 15 minutes, pass through a 100-mesh wet sieve, and then fill into the package to obtain the finished product.

[0047] Example 2 The biphasic herbicidal dispersible oil suspension of this embodiment has the following composition by percentage of total mass of the formulation: Oil phase A: mesosulfuron-methyl 1.2%, diflubenzuron 3.0%, clodinafop-propargyl 7.8%, safener A (pyrazosulfuron-methyl) 2.2%, oil phase solvent (methyl oleate and soybean methyl ester in a 2:1 mass ratio) 42.0%, oil phase emulsifier 6.3%, and oil phase dispersant (organo-bentonite) 12.5%. Nano-aqueous phase B: safener B (pyrazosulfuron-methyl) 2.0%, hydrophilic co-solvent 5.0%, water 16.5%, aqueous phase emulsifier 1.0%, and polymeric dispersant (maleic anhydride copolymer) 0.5%.

[0048] In the oil phase A, the mass ratio of mesosulfuron-methyl, diflubenzuron, and clodinafop-propargyl is 1.2:3.0:7.8; the mass ratio of safener A to the total mass of the three herbicides is 0.183; the mass ratio of oil phase emulsifier to oil phase dispersant is 1:2.0; the mass ratio of hydrophilic cosolvent to aqueous phase emulsifier is 5:1; and the mass ratio of oil phase A to nano-aqueous phase B is 7.5:2.5.

[0049] The biphasic herbicidal dispersible oil suspension is prepared by the following steps: S1: The oil phase solvent (a mixture of methyl oleate and soybean oil methyl ester in a mass ratio of 2:1) is added to a premixing tank. The oil phase dispersant (organo-bentonite) is slowly added at a shear speed of 2500 rpm, and pre-wetting is carried out for 15 minutes. Then, the oil phase emulsifier (a mixture of calcium dodecylbenzenesulfonate and nonylphenol polyoxyethylene ether) is added, and shear dispersion is continued for 8 minutes to obtain the oil phase base material.

[0050] S2: Maintaining shear conditions, add diflubenzuron, mesosulfuron-methyl, and clodinafop-propargyl sequentially to the oil phase base material, and shear disperse each component for 7 minutes after addition. Finally, add the safener A (clodinafop-propargyl) and continue homogenization for 12 minutes to obtain the oil phase slurry.

[0051] S3: In another container, add water, and at a shear speed of 3000 rpm, add the hydrophilic co-solvent (a mixture of glycerol and dipropylene glycol methyl ether in a mass ratio of 1:2.5), the aqueous emulsifier, the polymeric dispersant, and the safener B (pyrazole oxychloride). Shear homogenize for 20 minutes to obtain nano-aqueous phase B slurry.

[0052] S4: The oil phase slurry and the nano-aqueous phase B slurry are mixed at a mass ratio of 7.5:2.5 and then ground in a two-stage sand mill. The grinding pressure is controlled at 0.25 MPa, the outlet temperature is not higher than 35℃, and the cumulative grinding time is 55 minutes.

[0053] S5: Cool the product after sand milling to 28°C, degas for 15 minutes, pass through a 100-mesh wet sieve, and then fill into the package to obtain the finished product.

[0054] Example 3 The biphasic herbicidal oil-dispersible suspension of this embodiment comprises the following components by weight percentage of the total formulation: Oil phase A: 1.5% mesosulfuron-methyl, 3.5% diflubenzuron, 10.0% clodinafop-propargyl, 3.0% safener A (pyrazosulfuron-methyl), 35.0% oil phase solvent (caprylic / capric diglyceride), 5.5% oil phase emulsifier, and 11.5% oil phase dispersant (organo-bentonite). Nano-aqueous phase B: 3.0% safener B (pyrazosulfuron-methyl), 8.0% hydrophilic co-solvent, 16.0% water, 1.6% aqueous phase emulsifier, and 1.4% polymeric dispersant (acrylic acid copolymer).

[0055] In the oil phase A, the mass ratio of mesosulfuron-methyl, diflubenzuron, and clodinafop-propargyl is 1.5:3.5:10.0; the mass ratio of safener A to the total mass of the three herbicides is 0.20; the mass ratio of oil phase emulsifier to oil phase dispersant is 1:2.1; the mass ratio of hydrophilic cosolvent to aqueous phase emulsifier is 5:1; and the mass ratio of oil phase A to nano-aqueous phase B is 7:3.

[0056] The biphasic herbicidal dispersible oil suspension is prepared by the following steps: S1: Add the oil phase solvent (caprylic / capric diglyceride) to a premixing tank, and slowly add the oil phase dispersant (organo-bentonite) at a shear speed of 2500 rpm, pre-wetting for 15 minutes. Then add the oil phase emulsifier (tristyrylphenol polyoxyethylene ether), and continue shear dispersion for 8 minutes to obtain the oil phase base material.

[0057] S2: Maintaining shear conditions, add diflubenzuron, mesosulfuron-methyl, and clodinafop-propargyl sequentially to the oil phase base material, and shear disperse each component for 7 minutes after addition. Finally, add the safener A (clodinafop-propargyl) and continue homogenization for 12 minutes to obtain the oil phase slurry.

[0058] S3: In another container, add water, and at a shear speed of 3000 rpm, add the hydrophilic co-solvent (N-methylpyrrolidone), the aqueous emulsifier, the polymeric dispersant, and the safener B (pyrazole oxychloride). Shear homogenize for 20 minutes to obtain nano-aqueous phase B slurry.

[0059] S4: The oil phase slurry and the nano-aqueous phase B slurry are mixed at a mass ratio of 7:3 and then ground using a two-stage sand mill. The first stage of sand milling is for rapid crushing, approximately 20 minutes; the second stage of sand milling is for particle size reduction, approximately 30 minutes; the total grinding time is 50 minutes. The grinding pressure is controlled at 0.28 MPa, and the outlet temperature is controlled at 33℃ through circulating cooling.

[0060] S5: Cool the product after sand milling to 28°C, degas for 15 minutes, pass through a 100-mesh wet sieve, and then fill into the package to obtain the finished product.

[0061] Comparative Example 1 This comparative example provides a single-phase dispersible oil suspension, the composition of which is as follows, based on the total mass percentage of the formulation: The composition includes: 3.0% mesosulfuron-methyl, 5.0% diflubenzuron, 10.0% clodinafop-propargyl, 2.5% safer A (pyrazole pyrazole), 3.0% oil phase solvent (methyl oleate and soybean oil methyl ester in a 2:1 mass ratio), 8.0% oil phase emulsifier (calcium dodecylbenzenesulfonate and nonylphenol polyoxyethylene ether), and 6.0% oil phase dispersant (organo-bentonite).

[0062] Compared with Example 2, this comparative example maintains the same variety of three herbicides and dual-safety agents, but uses a single-phase dispersible oil suspension formulation. All components are configured in a single oil phase and do not contain nano-aqueous phase B, i.e., it is anhydrous, free of hydrophilic cosolvents, free of aqueous emulsifiers and polymeric dispersants.

[0063] The single-phase dispersible oil suspension is prepared by the following steps: the oil phase solvent is added to a premix tank, and the oil phase dispersant, oil phase emulsifier, all three herbicides and two safeners are added sequentially under shear conditions. After high-speed shear pre-dispersion, the mixture is ground in one pass using a sand mill until the oil droplet size D90 ≤ 5.0 μm. After cooling and filtration, it is then filled into containers.

[0064] Comparative Example 2 This comparative example provides a biphasic system for which the distribution of the safety agent does not meet the requirements of the present invention, and its composition, based on the total mass percentage of the formulation, is as follows: Oil phase A: 3.0% mesosulfuron-methyl, 5.0% diflubenzuron, 10.0% clodinafop-propargyl, 1.5% safer A (pyrazole pyrazole), 2.0% safer B (pyrazole pyrazole), 20.5% oil phase solvent, 8.0% oil phase emulsifier, and 6.0% oil phase dispersant (organo-bentonite).

[0065] Nano-aqueous phase B: Safeguard A (pyrazole pyrazole) 1.0%, Safeguard B (pyrazole pyrazole) 1.0%, hydrophilic cosolvent 12.0%, water 25.0%, aqueous emulsifier 3.0%, polymeric dispersant (maleic anhydride copolymer) 2.0%.

[0066] The preparation steps of the two-phase system are the same as in Example 2, except that: S2: after adding the herbicide to the oil phase base material, the safety agent B measured in the oil phase A is also added. S3: when preparing the nano-aqueous phase B slurry, the safety agent A measured in the slurry is added.

[0067] Comparative Example 3 This comparative example provides a biphasic system containing only a single safener, the composition of which is as follows, based on the percentage of total mass of the formulation: Oil phase A: 3.0% mesosulfuron-methyl, 5.0% diflubenzuron, 10.0% clodinafop-propargyl, 2.5% safer agent A (clodinafop-propargyl), 21.5% oil phase solvent, 8.0% oil phase emulsifier, and 6.0% oil phase dispersant (organo-bentonite).

[0068] Nano-aqueous phase B: 12.0% hydrophilic cosolvent, 27.0% water, 3.0% aqueous emulsifier, and 2.0% polymeric dispersant (maleic anhydride copolymer).

[0069] The preparation steps of the biphase system are the same as in Example 2, but the safener B (pyrazole herbicide) is not added in step S3.

[0070] Comparative Example 4 This comparative example provides a biphasic system containing only a single safener, the composition of which is as follows, based on the percentage of total mass of the formulation: Oil phase A: 3.0% mesosulfuron-methyl, 5.0% diflubenzuron, 10.0% clodinafop-propargyl, 23.0% oil phase solvent, 8.0% oil phase emulsifier, and 6.0% oil phase dispersant (organo-bentonite).

[0071] Nano-aqueous phase B: 3.0% safer agent B (pyrazole glufosinate), 12.0% hydrophilic cosolvent, 25.0% water, 3.0% aqueous emulsifier, and 2.0% polymeric dispersant (maleic anhydride copolymer).

[0072] The preparation steps of the biphase system are the same as in Example 2, but the safer A (methoxyphen ...

[0073] Comparative Example 5 This comparative example provides a single-phase dispersible oil suspension with low active ingredient content and no specific safener system. Its composition, by percentage of total mass of the formulation, is as follows: 0.6% mesosulfuron-methyl, 0.4% diflubenzuron, 7.0% clodinafop-propargyl, 76.0% oil phase solvent, 10.0% oil phase emulsifier (ammonium dodecyl sulfate), 5.0% oil phase dispersant (sodium methylene bis(naphthalene) sulfonate), and 1.0% thickener (xanthan gum).

[0074] The single-phase dispersible oil suspension is prepared by conventional single-phase OD process: after mixing all components, it is pre-dispersed by high-speed shearing, then ground to the required particle size in one pass using a sand mill, and finally packaged after post-processing.

[0075] Experimental Example 1: Determination of Physicochemical Properties and Stability of Formulations (1) Experimental objective: To verify the particle size standard that the biphasic herbicidal dispersible oil suspensions prepared in Examples 1-3 of this invention can achieve, and to systematically evaluate their physical stability under hot storage, cold storage and centrifugation conditions. By comparing with Comparative Examples 1-5, the technical advantages of the biphasic system of this invention are clarified.

[0076] (2) Test materials and grouping: The test materials were prepared according to the description of Examples 1-3 and Comparative Examples 1-5, and were numbered as follows: T1, T2, T3, C1, C2, C3, C4, C5. Each sample was prepared independently in 3 batches (n=3). All tests were performed on each batch of samples, and the results were the average of three parallel determinations.

[0077] (3) Indicators and Measurement Methods Oil phase A droplet size: The size was determined using a laser particle size analyzer based on the principle of wet dispersion. Before testing, the sample was diluted with deionized water at a mass ratio of 1:30 and gently shaken. Nanoparticle size of aqueous phase B: The size was determined using a dynamic light scattering instrument. The diluted sample was taken and its aqueous dispersion was separated for testing. Suspension rate and dilution stability: Performed according to the International Committee for Collaboration on Pesticide Analysis (ICPA) standard methods MT 15 and MT 36; Thermal storage stability: The sealed sample was placed in a constant temperature incubator at 54℃±2℃ for 14 consecutive days. After that, it was taken out and allowed to return to room temperature. The changes in its appearance were observed and recorded. Cold storage stability: The sealed sample was placed in a refrigerator at 0℃±2℃ for 7 consecutive days, then removed and brought to room temperature. The changes in appearance were observed and recorded. Centrifugation stability: Place the sample in a centrifuge tube and centrifuge at 3000 r / min for 30 minutes. Observe whether stratification, flocculation or sedimentation occurs.

[0078] The test results are shown in Tables 1 and 2: Table 1 Initial particle size and physicochemical properties of each sample

[0079] Note: "—" indicates that the sample is a single-phase system without an independent nano-aqueous phase B structure.

[0080] As shown in Table 1, Comparative Examples 1 and 5 could not form a nano-aqueous phase B structure, and their oil droplet D90 was significantly larger than that of the embodiments of the present invention, and their suspension rate was relatively low. Although Comparative Example 2 is a two-phase system, the particle size D90 of its nano-aqueous phase B has significantly exceeded the upper limit of 800 nm, and its suspension rate is the lowest, indicating that incorrect safety agent distribution seriously undermines the stability of the nano-aqueous phase structure.

[0081] Table 2 Storage and Stress Stability Performance

[0082] As shown in Table 2, Examples 1-3 of the present invention exhibit excellent physical stability under hot storage, cold storage and centrifugation conditions, mainly characterized by no stratification, slight sedimentation and reversibility.

[0083] Experimental Example 2: Determination of the efficacy of herbal medicines and weed control in indoor potted plants (1) Experimental objective: This experiment aims to compare the control effects of Examples 1-3 of the present invention and each comparative example on major annual weeds in wheat fields through indoor pot cultivation.

[0084] (2) Experimental materials and methods: Crops: Winter wheat (variety: Jimai 22); Weeds: Jointed goatgrass, wild oats, wild wheatgrass, and shepherd's purse.

[0085] Experimental groups: T1, T2, T3, C1, C2, C3, C4, C5; Control group: CK (water control).

[0086] Experimental conditions: Plastic pots with a diameter of 12 cm and a height of 11 cm were used and the experiment was conducted in a greenhouse. The day and night temperature of the greenhouse was controlled at 25℃ / 18℃. Foliar spraying was carried out when the wheat and all the test weeds grew to the 2-3 leaf stage.

[0087] Experimental design: Each treatment was set up with 4 replicates (n=4), and 10 seedlings were planted per pot.

[0088] Dosage regimen: The recommended dose is set as "total effective ingredient = standard dose 1×", and 0.8× and 1.2× dose gradients are added for duration of efficacy analysis.

[0089] Liquid spraying rate: 450 L / hm².

[0090] (3) Indicators and Measurement Methods Fourteen and twenty-one days after the treatment, the above-ground parts of all the weeds in each pot were cut and their fresh weight was measured.

[0091] Weed control efficacy (E) is calculated using the following formula:

[0092] In the formula, T represents the fresh weight of weeds in the treatment group, and C represents the fresh weight of weeds in the water control group.

[0093] The test results are shown in Tables 3 and 4: Table 3. Weed control efficacy (%) 14 days after application

[0094] As shown in Table 3, 14 days after application, Examples 1-3 of the present invention showed excellent control efficacy against all tested weeds, with an overall control efficacy level of approximately 87.8% to 96.5%. Among them, Examples 2 and 3 with the preferred formulations showed particularly outstanding control efficacy, with control efficacy exceeding 92% against all weeds.

[0095] Table 4. Weed control efficacy (%) 21 days after application

[0096] As shown in Table 4, the efficacy of each embodiment of the present invention showed the smallest decline after 21 days, demonstrating excellent sustained efficacy. In particular, Embodiments 2 and 3 maintained a control efficacy of over 90% against noxious grass weeds (jointed goatgrass, wild oats, and wild wheatgrass).

[0097] Experimental Example 3: Crop Safety Evaluation (1) Experimental objective: This experiment aims to verify the positive effect of the directional distribution of safener A and safener B in oil phase A and nano-aqueous phase B in this invention on reducing the phytotoxicity of wheat crops by the ternary compound herbicide of mesosulfuron-methyl, diflubenzuron and clodinafop-propargyl.

[0098] (2) Experimental materials and methods Experimental system: This experiment used the same potted plant system, pesticide dosage, and foliar spraying conditions as Experiment Example 2; Experimental replication: Each treatment was set up with 4 replicates (n=4).

[0099] (3) Indicators and Measurement Methods: Phytotoxicity rating: Visual assessment was conducted using a 0-100 point scale (0 points indicates no phytotoxicity symptoms, 100 points indicates complete plant death), and the results were recorded 3, 7 and 14 days after application.

[0100] Plant height inhibition rate: Plant height was measured 14 days after application, and the inhibition rate relative to the water control group was calculated.

[0101] The test results are shown in Table 5: Table 5. Herbicide damage score and plant height inhibition rate of wheat

[0102] As shown in Table 5, the phytotoxicity scores and final plant height inhibition rates of Examples 1-3, which employ a biphasic structure and targeted distribution of the safener, were significantly lower than those of all comparative examples at each observation period. In particular, the phytotoxicity scores of Examples 2 and 3 had dropped to approximately 1.0-1.2 points 14 days after application, and the plants had basically recovered, demonstrating outstanding crop safety. In contrast, the phytotoxicity of Comparative Examples 1 and 5, which use a single-phase system, was more severe and recovery was slower. Comparative Example 2, which had a mismatch in the distribution of the safener, had the highest phytotoxicity. However, the phytotoxicity of Comparative Examples 3 and 4, which contain only a single safener, was still significantly higher than that of Examples 1-3, further verifying the synergistic advantages of dual safeners in the biphasic system.

[0103] Experiment Example 4: Field Plot Validation (1) Experimental objective: This experiment aims to verify the comprehensive control efficacy, duration of effect and safety of the preferred formulation of the present invention (Example 2, i.e. T2) against weeds under field conditions.

[0104] (2) Experimental site and crop Location: Experimental field in the main winter wheat producing area of ​​North China; Soil type: loam; pH value: 7.2; Weed community: dominated by grassy weeds such as wild oats, wild wheatgrass, and jointed goatgrass, with broadleaf weeds mainly consisting of shepherd's purse; Test crop: winter wheat (variety: Jimai 22); Experimental design: A randomized block design was adopted, with 3 replicates per treatment, a plot area of ​​30 m², and a 0.5-meter isolation zone between plots; Application time: from the late greening stage to the early jointing stage of wheat, when weeds in the field are in the 2-3 leaf stage.

[0105] (3) Experimental treatment and application of pesticides: CK: Water control; T2: Biphasic herbicidal oil-dispersible suspension of the present invention (Example 2), recommended application dose (1×); C5: Single-phase 8% dispersible oil suspension (Comparative Example 5), application dose of the same active ingredient.

[0106] Liquid spraying rate: 450 L / hm².

[0107] (4) Indicators and Measurement Methods Weed control efficacy: The number of weed plants and the fresh weight of the aboveground parts were investigated 14 and 28 days after the application of the herbicide, and the control efficacy per plant and the control efficacy per fresh weight were calculated.

[0108] Crop safety: Phytotoxicity scores (0-100 points) were assessed 7 and 14 days after application.

[0109] Yield composition: At maturity, the number of ears per unit area and the weight of a thousand grains were investigated and converted into theoretical yield.

[0110] The test results are shown in Tables 6 and 7: Table 6. Weed control efficacy in the field (%)

[0111] As shown in Table 6, the control efficacy of the product of this invention on both the strain and fresh weight at 14 and 28 days after application was significantly higher than that of the comparative example 5.

[0112] Table 7 Field wheat safety and yield

[0113] As shown in Table 7: Crop safety: The product of this invention causes very little phytotoxicity to wheat. The scores at 7 and 14 days after application are significantly lower than those of the C5 treatment, and the symptoms recover quickly.

[0114] Yield performance: Compared with the control (CK), the T2 treatment showed a slight increase in the number of spikes, thousand-grain weight, and final yield. However, the C5 treatment, due to relatively severe herbicide damage, resulted in a lower number of spikes and thousand-grain weight than both CK and T2, and a lower final yield than CK.

[0115] Based on the above embodiments and experimental results, the biphasic herbicidal dispersible oil suspension and its preparation method provided by the present invention have the following significant beneficial effects: (1) Excellent physical stability: By constructing a two-phase structure of oil phase A and nano-aqueous phase B, and optimizing the two-stage sand milling process parameters (pressure 0.2~0.3MPa, time 40~60min, temperature ≤35℃), a stable composite dispersion system with oil droplet D90≤5.0μm and nano-aqueous phase D90≤800nm ​​was successfully obtained. This system exhibits excellent structural integrity under harsh conditions such as hot storage, cold storage and centrifugation, with no stratification, no flocculation, slight sedimentation and reversible redispersion, solving the engineering problems of particle size coarsening and oil-water separation that are prone to occur in traditional single-phase dispersible oil suspensions.

[0116] (2) Synergistic protection mechanism of safeners: By directionally distributing safener A (≥80%) and safener B (≥70%) to oil phase A and nano-aqueous phase B respectively, efficient synergistic protection of crops is achieved. After application, safener B in nano-aqueous phase B can first form a protective layer at the leaf interface; at the same time, safener A in oil phase A is deposited, absorbed and translocated synchronously with the ternary herbicide oil droplets. This ordered action in time and space constitutes dual protection, significantly reducing crop phytotoxicity.

[0117] (3) Improved weed control efficacy and persistence: With optimized ternary herbicide ratio and safener proportion, the biphasic nanosystem of this invention significantly improved the control efficacy against major weeds such as jointed goatgrass, wild oats, wild wheatgrass, and shepherd's purse, and especially demonstrated excellent persistence. This indicates that the formulation effectively improves the spread and penetration of the herbicide on the leaf surface and the efficiency of translocation within the weeds, and prolongs the action time of the active ingredient.

[0118] (4) Balancing efficient weed control with crop safety: Through the synergistic effect of the biphasic structure and the targeted distribution of dual safeners, this invention ensures efficient and long-lasting control of noxious weeds while greatly improving the safety for wheat crops. Field trials have confirmed that the solution of this invention can achieve the comprehensive effect of "minimal herbicide damage, rapid recovery, and stable and increased yield," significantly broadening the safety window for ternary high-efficiency herbicides in practical applications and providing a better solution for the integrated management of weeds in wheat fields.

[0119] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A biphase herbicidal dispersible oil suspension characterized in that, The formulation, by weight percentage, consists of an oil phase A and a nano-aqueous phase B. Oil phase A comprises 1-5% mesosulfuron-methyl, 2-8% diflubenzuron, 5-15% clodinafop-propargyl, 1-4% safer A, 20-50% oil phase solvent, and 5-20% total oil phase emulsifier and dispersant. Nano-aqueous phase B comprises 1-4% safer B, 5-20% hydrophilic co-solvent, 15-40% water, and 1-10% total aqueous phase emulsifier and polymeric dispersant. The total content of mesosulfuron-methyl, diflubenzuron and clodinafop-propargyl is 8-15%, the total content of safener A and safener B is 3-7%, at least 70% of the total mass of safener B is allocated to the nano-aqueous phase B, at least 80% of the total mass of safener A is allocated to the oil phase A, and the mass ratio of oil phase A to nano-aqueous phase B is 8:2-7:

3.

2. The biphase herbicidal oil dispersible suspension according to claim 1, characterized in that, Safener A is pyrazosulfuron-methyl, and safener B is pyrazosulfuron-methyl.

3. The biphase herbicidal oil dispersible suspension according to claim 1, characterized in that, The mass ratio of mesosulfuron-methyl, diflubenzuron and clodinafop-propargyl in oil phase A is (0.5~1.5):(1.5~3.5):(5.0~10.0), and the mass ratio of safener A to the total amount of the three herbicides is 0.15~0.

40.

4. The biphase herbicidal oil dispersible suspension according to claim 1, characterized in that, The oil phase solvent is selected from one or more combinations of methyl oleate, rapeseed oil methyl oleate, soybean oil methyl oleate, palm oil methyl oleate, isopropyl myristate and caprylic / capric diglyceride, and the oil phase emulsifier includes at least one of tristyrylphenol polyoxyethylene ether and calcium dodecylbenzenesulfonate.

5. The biphase herbicidal dispersible oil suspension according to claim 1, characterized in that, The oil phase dispersant includes organic bentonite, and the mass ratio of oil phase emulsifier to oil phase dispersant is 1:1 to 1:

3.

6. The biphase herbicidal dispersible oil suspension according to claim 1, characterized in that, The hydrophilic cosolvent is selected from one or more combinations of propylene glycol, glycerol, N-methylpyrrolidone and dipropylene glycol methyl ether.

7. The biphase herbicidal dispersible oil suspension according to claim 1, characterized in that, The aqueous emulsifier is a nonionic surfactant with an HLB value greater than 10, and the polymeric dispersant is an acrylic copolymer dispersant or a maleic anhydride copolymer dispersant; and the oil droplet volume distribution D50 of the suspending agent is 1.0~3.0μm and D90 is not greater than 5.0μm, and the D50 of the nano aqueous phase B is 50~500nm and D90 is not greater than 800nm.

8. A process for the preparation of a herbicidal biphasic oil dispersible suspension according to any one of claims 1 to 7, characterized in that, include: S1. Add the oil phase solvent, oil phase emulsifier and oil phase dispersant to the premix tank and shear and disperse to form the oil phase base material; S2. Under shearing conditions, diflubenzuron, mesosulfuron-methyl, clodinafop-propargyl and safer A are added sequentially to the oil phase base material, and shearing and homogenization are continued to obtain an oil phase slurry, wherein the oil phase slurry is oil phase A. S3. Prepare an aqueous phase separately by adding a hydrophilic co-solvent, an aqueous emulsifier, a polymeric dispersant, and a safety agent B to water and then shearing and homogenizing to obtain a nano-aqueous slurry, wherein the nano-aqueous slurry is nano-aqueous phase B; S4. The oil phase slurry obtained in step S2 and the nano aqueous phase slurry obtained in step S3 are mixed at a mass ratio of 8:2 to 7:3 and then subjected to two-stage sand milling. The outlet temperature is controlled to be no higher than 35°C and the grinding chamber pressure is no higher than 0.3MPa until the oil droplet volume distribution D90 of the obtained suspension is no greater than 5.0μm and the D90 of the nano aqueous phase slurry is no greater than 800nm. S5. Cooling, degassing, wet sieving, filling and sealing.

9. The production method according to claim 8, characterized by, In step S1, organic bentonite is first added to the oil phase solvent and pre-wetted at 2000~3500 rpm for 10~20 min, and then the oil phase emulsifier is added; in step S2, the order of adding the three herbicides is first diflubenzuron, then mesosulfuron-methyl, and then clodinafop-propargyl.

10. The production method according to claim 8 or 9, characterized by, In step S3, the mass ratio of the hydrophilic cosolvent to the aqueous emulsifier is 2:1 to 5:1, and the polymeric dispersant is 1 to 3% of the total mass of the nano-aqueous phase B. In step S4, the pressure in the sand mill grinding chamber is 0.2 to 0.3 MPa, and the cumulative grinding time is 40 to 60 min.

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