Nano dispersible oil suspending agent as well as preparation method and application thereof

Abstract

The invention relates to the technical field of pesticides, and discloses a nano dispersible oil suspending agent as well as a preparation method and application thereof. The method comprises the following steps: (1) mixing a first effective component, a solvent, a part of an emulsifier and water to obtain a first material; and (2) mixing the second effective component with the first material, then adding the dispersing agent, the residual emulsifier, the thickening agent and methyl oleate, and sanding to obtain the nano dispersible oil suspending agent. The preparation method of the nano dispersible oil suspending agent provided by the invention solves the problem that cyhalofop-butyl is easy to crystallize at a low temperature, solves the problem of low sanding efficiency caused by soft particles when cyhalofop-butyl raw medicine is sanded by a conventional method, can obtain a nano-scale pesticide preparation in a shorter time, and is suitable for large-scale popularization and application. And the prepared nano dispersible oil suspending agent has the advantage of stability under the conditions of room temperature, high temperature and low temperature.

Description

Technical Field

[0001] This invention relates to the field of pesticide technology, specifically to a nano-dispersible oil suspension, its preparation method, and its application. Background Technology

[0002] Dispersible oil suspensions (dosage form code OD) are stable suspensions of liquid formulations in which the active ingredient is dispersed in a non-aqueous medium as solid particles. Essentially, dispersible oil suspensions belong to the suspension dosage form. The main difference between them and aqueous suspensions (dosage form code SC) is that the former uses mineral oil or vegetable oil as the dispersion medium, while the latter uses water. The difference between dispersible oil suspensions and oil suspensions (dosage form code OF) is that the former can be diluted with water and dispersed and emulsified in water, while the latter can only be diluted with oil.

[0003] Because dispersible oil suspensions contain a large amount of emulsifier (comparable to microemulsions) and the medium is oil-based, they have excellent compatibility with the waxy layer of plant leaves, thus exhibiting good adhesion and spreading properties. They easily adhere to plant targets or smooth leaf surfaces, and their efficacy is comparable to or even surpasses that of emulsifiable concentrates. They are a green and environmentally friendly formulation with great potential for future development.

[0004] Nanopesticides are pesticide formulations constructed based on nanotechnology. The core of this technology is to prepare pesticide active ingredients (technical grade pesticides) and carrier materials (such as nanoparticles, polymers, etc.) into a dispersion system with a particle size of 1-1000 nm through specific processes. Essentially, they optimize the application performance of pesticides by nano-sized particles and functionalizing the carrier.

[0005] There is an urgent need to develop a method for the efficient preparation of nano-dispersible oil suspensions. Summary of the Invention

[0006] The purpose of this invention is to overcome the problems existing in the prior art and provide a nano-dispersible oil suspension, its preparation method and application.

[0007] To achieve the above objectives, the first aspect of the present invention provides a method for preparing a nano-dispersible oil suspension, wherein the method includes the following steps: (1) The first active ingredient, solvent, a portion of emulsifier and water are mixed to obtain the first material; (2) The second active ingredient and the first material are mixed, and then the dispersant, the remaining emulsifier, the thickener and methyl oleate are added and then the mixture is milled to obtain the nano-dispersible oil suspension.

[0008] A second aspect of the present invention provides a nano-dispersible oil suspension obtained according to the preparation method described in the first aspect.

[0009] A third aspect of the present invention provides the application of the nano-dispersible oil suspension according to the second aspect in the control of annual broadleaf weeds in paddy fields.

[0010] The beneficial technical effects achieved by the present invention through the above technical solution are as follows: (1) The preparation method of nano-dispersible oil suspension provided by the present invention solves the problem of easy low-temperature crystallization of cyhalofop-butyl and the problem of low grinding efficiency due to the softness of the particles when grinding cyhalofop-butyl technical material together using conventional methods. It can obtain nano-scale pesticide formulations in a shorter time, and the prepared nano-dispersible oil suspension has the advantage of stability under room temperature and high and low temperature conditions.

[0011] (2) The particle size D90 of the nano-dispersible oil suspension prepared by the present invention is ≤600nm, which is only 1 / 10 of the particle size of ordinary dispersible oil suspension. This helps the active ingredient to be better adsorbed and penetrated into the target, thus improving the efficacy; it helps the active ingredient particles to be better suspended in the medium, thus greatly improving the stability of the formulation; it helps pesticide particles remaining in the environment to be more easily degraded by microorganisms, thus improving environmental safety and reducing residues. Detailed Implementation

[0012] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0013] The first aspect of this invention provides a method for preparing a nano-dispersible oil suspension, wherein the method includes the following steps: (1) The first active ingredient, solvent, a portion of emulsifier and water are mixed to obtain the first material; (2) The second active ingredient and the first material are mixed, and then the dispersant, the remaining emulsifier, the thickener and methyl oleate are added and then the mixture is milled to obtain the nano-dispersible oil suspension.

[0014] This invention effectively solves the problems of low-temperature precipitation of active ingredients and the difficulty of milling dispersible oil suspensions to the nanoscale using conventional methods, thereby improving stability and milling efficiency. The nano-dispersible oil suspensions provided by this invention can improve the adhesion of drug solutions to targets, have small particle sizes, good stability, and are more easily absorbed by the target, thus enhancing drug efficacy.

[0015] In some embodiments of the present invention, the first active ingredient in step (1) is cyhalofop-butyl.

[0016] In some embodiments of the present invention, the second active ingredient in step (2) is penoxsulam.

[0017] In some embodiments of the present invention, the first material further includes methyl oleate. Methyl oleate can be used as a solvent.

[0018] In some embodiments of the present invention, the nano-dispersible oil suspension comprises the following raw materials by mass percentage: 5-35% active ingredient; 2-8% dispersant; 10-25% emulsifier; 10-30% solvent; 0.5-2% thickener; 1-5% water; and the balance being methyl oleate.

[0019] In this invention, the active ingredient refers to the sum of the first active ingredient and the second active ingredient. In this invention, the mass percentage of the active ingredient is calculated based on its pure substance.

[0020] In some embodiments of the present invention, the nano-dispersible oil suspension comprises the following raw materials by mass percentage: 8.5-34% active ingredient; 2% dispersant; 17.5-21.3% emulsifier; 15-26.3% solvent; 0.5% thickener; 2.5% water; and the balance being methyl oleate.

[0021] In some embodiments of the present invention, the nano-dispersible oil suspension comprises the following raw materials by mass percentage: 8.5% active ingredient; 2% dispersant; 17.5% emulsifier; 15% solvent; 0.5% thickener; 2.5% water; and the balance being methyl oleate.

[0022] In some embodiments of the present invention, the nano-dispersible oil suspension comprises the following raw materials by mass percentage: 17% active ingredient; 2% dispersant; 17.5% emulsifier; 20% solvent; 0.5% thickener; 2.5% water; and the balance being methyl oleate.

[0023] In some embodiments of the present invention, the nano-dispersible oil suspension comprises the following raw materials by mass percentage: 25.5% active ingredient; 2% dispersant; 18.4% emulsifier; 19.7% solvent; 0.5% thickener; 2.5% water; and the balance being methyl oleate.

[0024] In some embodiments of the present invention, the nano-dispersible oil suspension comprises the following raw materials by mass percentage: 34% active ingredient; 2% dispersant; 21.3% emulsifier; 26.3% solvent; 0.5% thickener; 2.5% water; and the balance being methyl oleate.

[0025] In some embodiments of the present invention, the mass percentage of the first active ingredient is 5-30%, preferably 15%.

[0026] In some embodiments of the present invention, the mass percentage of the second active ingredient is 1-5%, preferably 2%.

[0027] In some embodiments of the present invention, the solvent is selected from at least one of cyclohexanone, 100# solvent oil, 150# solvent oil, 200# solvent oil, N,N-dimethylacetamide, isophorone, and soybean oil.

[0028] In some embodiments of the present invention, the emulsifier is selected from at least two of Atlas G 1086, Atlas G 1096, Atlox 4838B, Atlox 4817B, Bamboo Oil 5050PB, Bamboo Oil CP120, Bamboo Oil OD3000, Bamboo Oil OD1200, Taihua 505W, Taihua 601, and Taihua 602.

[0029] In some embodiments of the present invention, the dispersant is selected from at least one of Atlox 4912, Atlox 4914, Zephrym PD 2206, Atlox LP-1, ZEPHRYM PD 7000, Bamboo Oil EP60P, and Bamboo Oil BXC.

[0030] In some embodiments of the present invention, the thickener is selected from at least one of organobentonite, silica, magnesium aluminum silicate, and attapulgite.

[0031] In some embodiments of the present invention, the milling time is 30-50 minutes, preferably 45 minutes. Using the method of the present invention, nanoscale dispersible oil suspensions can be obtained with a shorter milling time.

[0032] In some embodiments of the present invention, the mass ratio of the emulsifier used in steps (1) and (2) is 1-2:1, preferably 3:2.

[0033] A second aspect of the present invention provides a nano-dispersible oil suspension obtained according to the preparation method described in the first aspect.

[0034] In some embodiments of the present invention, the particle size D90 of the nano-dispersible oil suspension is ≤600nm.

[0035] A third aspect of the present invention provides the application of the nano-dispersible oil suspension according to the second aspect in the control of annual broadleaf weeds in paddy fields.

[0036] In some embodiments of the present invention, the weeds are selected from at least one of goosegrass, Echinochloa crus-galli, and Sagittaria sagittifolia.

[0037] The present invention will be described in detail below through embodiments.

[0038] Unless otherwise specified in the following examples and comparative examples, all conditions were performed under standard conditions or conditions recommended by the manufacturer. Reagents or instruments used, unless otherwise specified, are all commercially available products.

[0039] Source of materials: Cyhalofop-butyl: 98% purity, purchased from Nantong Taihe Chemical Co., Ltd. Penflusulfonamide: 98% purity, purchased from Shandong Binnong Technology Co., Ltd.

[0040] Example 1 This example illustrates the preparation of 1% penoxsulam•7.5% cyhalofop-butyl OD.

[0041] (1) Dissolve 15.4g of cyhalofop-butyl completely with 10g of cyclohexanone and 20g of 150# solvent oil, add 5g of Taihua 505W, 10g of Taihua 601 and 5g of deionized water and stir evenly. Finally, add methyl oleate to make up 100g to obtain the first material. (2) Mix 1.1g penoxsulam, 50g first material, 2g Zephrym PD 2206, 10g bamboo oil OD1200, 0.5g organic bentonite and 36.4g methyl oleate and shear evenly. Sand mill for 45min to obtain a particle size D90≤600nm, thus obtaining 1% penoxsulam•7.5% cyhalofop-butyl OD.

[0042] Example 2 This example illustrates the preparation of 2% penoxsulam•15% cyhalofop-butyl OD.

[0043] (1) Dissolve 30.7g of cyhalofop-butyl completely with 10g of cyclohexanone and 30g of 150# solvent oil, add 5g of Taihua 505W, 10g of Taihua 602 and 5g of deionized water and stir evenly. Finally, add methyl oleate to make up 100g to obtain the first material. (2) Mix 2.1g penoxsulam, 50g first material, 2g Zephrym PD 2206, 10g bamboo oil OD3000, 0.5g organic bentonite and 35.4g methyl oleate and shear evenly. Sand mill for 45min to obtain a particle size D90≤600nm, thus obtaining 2% penoxsulam•15% cyhalofop-butyl OD.

[0044] Example 3 This example illustrates the preparation of 3% penoxsulam•22.5% cyhalofop-butyl OD.

[0045] (1) Dissolve 40.9g of cyhalofop-butyl completely with 5g of N,N-dimethylacetamide and 30g of 150# solvent oil, add 5g of Taihua 505W, 10g of Taihua 602 and 5g of deionized water and stir evenly. Finally, add methyl oleate to make up 100g to obtain the first material. (2) Mix 3.1g penoxsulam, 56.25g first material, 2g Zephrym PD 2206, 10g bamboo oil OD3000, 0.5g organic bentonite and 28.15g methyl oleate and shear evenly. Sand mill for 45min to obtain a particle size D90≤600nm, thus obtaining 3% penoxsulam•22.5% cyhalofop-butyl OD.

[0046] Example 4 This example illustrates the preparation of 4% penoxsulam•30% cyhalofop-butyl OD.

[0047] (1) Dissolve 40.9g of cyhalofop-butyl completely with 5g of N,N-dimethylacetamide and 30g of 150# solvent oil, add 5g of Taihua 505W, 10g of Taihua 602 and 5g of deionized water and stir evenly. Finally, add methyl oleate to make up 100g to obtain the first material. (2) Mix 4.1g penoxsulam, 75g first material, 2g Zephrym PD 2206, 10g bamboo oil OD3000, 0.5g organic bentonite and 8.4g methyl oleate and shear evenly. Sand mill for 45min to obtain a particle size D90≤600nm, thus obtaining 4% penoxsulam•30% cyhalofop-butyl OD.

[0048] Comparative Example 1 Mix 2.1g penoxsulam, 15.4g cyhalofop-butyl, 2g Zephrym PD 2206, 15g bamboo oil OD3000, 0.5g organic bentonite and 35.4g methyl oleate and shear evenly. Sand mill for 80 minutes until the particle size D90 ≤ 8μm to obtain 2% penoxsulam•15% cyhalofop-butyl OD.

[0049] Comparative Example 2 Mix 2.1g penoxsulam, 15.4g cyhalofop-butyl, 2g Zephrym PD 2206, 15g bamboo oil OD3000, 0.5g organic bentonite and 35.4g methyl oleate and shear evenly. Sand mill for 135 minutes until the particle size D90≤600nm to obtain 2% penoxsulam•15% cyhalofop-butyl OD.

[0050] Test Example 1 Example 1 4. The particle size and stability of the dispersible oil suspensions prepared in Comparative Examples 1-2 were tested. The results are shown in Table 1.

[0051] Initial particle size and thermal storage particle size are both measured using LS. The D90 value was measured using a POP(9) laser particle size analyzer. The thermal storage particle size was determined by the DHP value at 54℃. After being placed in a 9162 electric thermostatic incubator for 14 days, the particles were removed and cooled to room temperature before measuring the D90 value.

[0052] Room temperature dispersion stability and thermal storage dispersion stability refer to the dispersion stability tested by method 4.11 in HG / T2467.11-2003 after 14 days of thermal storage at room temperature and 54℃, respectively.

[0053] Low-temperature stability: Conducted according to "2.2 Suspension Formulations" in GB / T 19137-2003 (placed at 0℃ for 7 days). In actual production, low-temperature stability tests can be conducted once every 3 months.

[0054] Thermal stability: Conducted according to the method in "4.4.1 Liquid Formulation" of GB / T 19136-2021 (stored at 54℃ for 14 days). In actual production, thermal stability tests can be conducted once every 3 months.

[0055] Table 1

[0056] As can be seen from the results in Table 1, the embodiments of the present invention can obtain nanoscale dispersed oil suspensions with a shorter grinding time, and have better stability under normal temperature and high and low temperature conditions.

[0057] Test Example 2 The experimental site was located in Fengxian District, Shanghai. The crop tested was rice, and the sowing method was transplanting. The experimental site was covered with weeds all year round, mainly including goosegrass, Echinochloa crus-galli, and Sagittaria sagittifolia.

[0058] The experiment consisted of 7 treatments: Examples 1-4, Comparative Examples 1-2, and a water control (CK). Each treatment was repeated 3 times, for a total of 21 plots, which were arranged in a randomized block design.

[0059] Application time: Apply pesticide at the 2-leaf-1-heart stage of rice, diluted with water and sprayed. Use a hand-held compressor sprayer for soil treatment; dosage of 10g of active ingredient per acre.

[0060] Three points were randomly selected from each plot at 10, 20, and 40 days after drug administration, with each point having an area of ​​0.25 m². 2 The control efficacy against annual broadleaf weeds was investigated separately.

[0061] Control efficacy = (Number of weeds in the control zone - Number of weeds in the treatment zone) / Number of weeds in the control zone × 100% The results are shown in Table 2.

[0062] Table 2

[0063] As shown in Table 2, the herbicidal efficacy of the dispersible oil suspensions prepared in Examples 1-4 of this invention is significantly better than that of the comparative examples. Comparing Examples 1-4, Comparative Example 2, and Comparative Example 1, it can be seen that the efficacy of the formulation at the nanoscale is significantly better than that of ordinary dispersible oil suspensions. Comparing Examples 1-4 with Comparative Example 2, it can be seen that the nano-dispersible oil suspension prepared by the preparation method provided by this invention has better efficacy.

[0064] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for preparing a nano-dispersible oil suspension, characterized in that, The method includes the following steps: (1) The first active ingredient, solvent, a portion of emulsifier and water are mixed to obtain the first material; (2) The second active ingredient and the first material are mixed, and then the dispersant, the remaining emulsifier, the thickener and methyl oleate are added and then the mixture is milled to obtain the nano-dispersible oil suspension.

2. The preparation method according to claim 1, wherein, In step (1), the first active ingredient is cyhalofop-butyl; Preferably, the second active ingredient in step (2) is penoxsulam; Preferably, the first material further includes methyl oleate.

3. The preparation method according to claim 1 or 2, wherein, The nano-dispersible oil suspension comprises the following raw materials by mass percentage: 5-35% active ingredient; 2-8% dispersant; 10-25% emulsifier; 10-30% solvent; 0.5-2% thickener; 1-5% water; and the balance being methyl oleate. Preferably, the nano-dispersible oil suspension comprises the following raw materials by mass percentage: 8.5-34% active ingredient; 2% dispersant; 17.5-21.3% emulsifier; 15-26.3% solvent; 0.5% thickener; 2.5% water; and the balance being methyl oleate. Preferably, the mass percentage of the first active ingredient is 5-30%, more preferably 15%; Preferably, the mass percentage of the second active ingredient is 1-5%, more preferably 2%.

4. The preparation method according to any one of claims 1-3, wherein, The solvent is selected from at least one of cyclohexanone, 100# solvent oil, 150# solvent oil, 200# solvent oil, N,N-dimethylacetamide, isophorone, and soybean oil; Preferably, the emulsifier is selected from at least two of Atlas G 1086, Atlas G 1096, Atlox 4838B, Atlox 4817B, Bamboo Oil 5050PB, Bamboo Oil CP120, Bamboo Oil OD3000, Bamboo Oil OD1200, Taihua 505W, Taihua 601, and Taihua 602.

5. The preparation method according to any one of claims 1-4, wherein, The dispersant is selected from at least one of the following: Atlox 4912, Atlox 4914, Zephrym PD 2206, Atlox LP-1, ZEPHRYM PD 7000, Bamboo Oil EP60P, and Bamboo Oil BXC. Preferably, the thickener is selected from at least one of organobentonite, silica, magnesium aluminum silicate, and attapulgite.

6. The preparation method according to any one of claims 1-5, wherein, The grinding time is 30-50 minutes, preferably 45 minutes.

7. The preparation method according to any one of claims 1-6, wherein, The mass ratio of the emulsifier used in steps (1) and (2) is 1-2:1, preferably 3:

2.

8. A nano-dispersible oil suspension obtained by the preparation method according to any one of claims 1-7.

9. The nano-dispersible oil suspension according to claim 8, wherein, The particle size D90 of the nano-dispersible oil suspension is ≤600nm.

10. The application of the nano-dispersible oil suspension according to claim 8 or 9 in the control of annual broadleaf weeds in paddy fields; Preferably, the weeds are selected from at least one of goosegrass, Echinochloa crus-galli, and Sagittaria sagittifolia.

Images