A reverse processing technology of pesticide suspending agent

Abstract

The present application belongs to the technical field of pesticide suspension concentrate preparation, and relates to a reverse processing technology of pesticide suspension concentrate. A certain amount of raw pesticide is dissolved in a solvent, and then a surfactant A is added and uniformly mixed to obtain a solvent phase; a crystal control regulator B and a crystal control polymer C are dissolved in water to obtain an anti-solvent phase; the two phases are mixed at a temperature of 15-50 DEG C under a certain stirring power or shearing power, and finally a thickening agent is added to the obtained suspension concentrate to obtain a target suspension concentrate product. The present application controls the size of raw pesticide crystal by using a "bottom-up" method, avoids the high-energy grinding process in the conventional suspension concentrate production process, improves the production efficiency, and reduces the production energy consumption. Compared with the conventional grinding method, the time required for producing each ton of product can be shortened by 1 / 3-1 / 2, and the energy consumption can be reduced by 30-50%, thereby improving the production efficiency and greatly reducing the energy consumption.

Description

Technical Field

[0001] This invention belongs to the field of pesticide suspension preparation technology, and relates to a reverse processing technology for pesticide suspension, particularly a process for bottom-up processing of pesticide suspension using crystal precipitation. Background Technology

[0002] Suspension concentrates are a type of water-based pesticide formulation. Due to their simple preparation process, low production cost, and high biological activity, they occupy a significant market share. Conventional pesticide suspension concentrate production methods use water as a medium and employ mechanical grinding to pulverize the active ingredient. Obtaining micro-nano-sized and uniform particle suspensions typically requires lengthy grinding processes, which are time-consuming and energy-intensive. Improving the production efficiency of water-based suspension concentrates and reducing energy consumption are urgent problems to be solved.

[0003] Crystallization is a solid-liquid separation method used in fine chemical and pharmaceutical products. It uses crystallization to separate and purify substances for further processing. Specifically, this method involves dissolving the solute in a solvent, then adding an antisolvent to achieve solute supersaturation, resulting in the precipitation of target crystals. Since this process does not form a pharmaceutical formulation, there are no requirements regarding crystal size or morphology. Currently, there are no reports of using this method to prepare pesticide aqueous suspensions. Controlling the crystal precipitation rate and size is crucial and challenging to meet the needs of industrial-scale pesticide formulation production and application. Summary of the Invention

[0004] This invention addresses the problems existing in the production of traditional pesticide suspensions by proposing a novel bottom-up process for processing pesticide suspensions using crystal precipitation.

[0005] To achieve the above objectives, the present invention is implemented using the following technical solution:

[0006] A process for bottom-up processing of pesticide suspensions using crystal precipitation is described below.

[0007] A certain mass of the active ingredient is dissolved in a solvent, and then surfactant A is added and mixed evenly to obtain the solvent phase. Crystal control regulator B and crystal control polymer C are dissolved in water to obtain the antisolvent phase. The two phases are mixed at a temperature of 15-50°C and a certain stirring power or shear power is selected. Finally, a thickener is added to the obtained suspension to obtain the target suspension product.

[0008] The pesticide suspension reverse processing technology proposed in this invention regulates the precipitation of crystals by changing solvent factors; this process is suitable for active ingredients in solid form. First, the solvent must be able to dissolve the pesticide and successfully precipitate crystals and complete the coating process to form solid particles. The solvent has the following characteristics: (1) the solvent has good solubility for the active ingredient; (2) the solvent has a certain solubility in water, which can make the active ingredient precipitate supersaturated quickly; (3) solvents of different polarities can be mixed to regulate the precipitation rate of the active ingredient and better control the morphology and particle size of the particles. Organic solvents include hydrophilic solvents: methanol, ethanol, acetone, isobutanol, n-propanol, isopropanol, tetrahydrofuran, ethylene glycol, propylene glycol, glycerol, dimethyl ether, ethyl acetate, N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), cyclohexanone, acetonitrile, etc.; hydrophobic solvents: petroleum ether, dichloromethane, xylene, toluene, benzene, solvent oil, n-hexane, methyl oleate. By screening single solvents and mixing different solvents, the crystal precipitation rate can be controlled, thereby obtaining particles with the target particle size and morphology.

[0009] The pesticide suspension reverse processing technology described above modifies the emulsifying ability of surfactant A on the solvent phase, fully emulsifying the solvent phase into droplets, thereby controlling the morphology, size, and crystal precipitation of particles in the suspension. The use of surfactant A is crucial: surfactants enable pesticide particles to disperse uniformly and form stable emulsions, preventing demulsification and other adverse phenomena. Furthermore, the use of surfactants improves the dispersibility, suspension, and stability of pesticides, thereby enhancing their effectiveness and application results. There are many different types of surfactants, including nonionic fatty alcohol block polyether emulsifiers, nonionic polyoxyethylene hydrogenated castor oil emulsifiers, nonionic hydroxyl polyethylene oxide block copolymer emulsifiers, nonionic styrene-phenol polyoxyethylene ether emulsifiers, anionic calcium dodecylbenzenesulfonate emulsifiers, nonionic alkylphenol and ethylene oxide condensate emulsifiers, nonionic polyoxyethylene and polyoxypropylene block polymer emulsifiers, nonionic polyoxyethylene sorbitan fatty acid ester emulsifiers, nonionic sorbitan fatty acid emulsifiers, and nonionic fatty alcohol polyoxyethylene ether emulsifiers, etc. This invention preferably uses nonionic emulsifiers. The amount of surfactant is controlled between 1-20%, resulting in excellent emulsifying effects. Surfactant A plays a regulatory role in the morphology and size of the particles, thereby obtaining suspension particles with the target particle size and morphology; surfactant A can be a combination of one or more surfactants.

[0010] As described above, in the reverse processing technology of pesticide suspensions, solid substances precipitate out after reaching saturation solubility in a solvent. This process involves the molecules changing from a freely moving state to an ordered arrangement. This technology controls crystal size by adding crystal control regulator B and crystal control polymer C. Crystal control regulator B is an anionic lignin sulfonate, a natural polyphenolic amphiphilic compound with strong adsorption capacity. Suitable lignin sulfonates for this technology should meet the following parameters: sulfonic acid group on a benzene ring, degree of sulfonation 0.8-1.5, and molecular weight 8000-12000. Crystal control copolymer C is a carboxylate terpolymer that should simultaneously possess three hydrophilic groups (carboxylic acid group, sulfonic acid group, and hydroxyl group) and a hydrophobic polystyrene group, with a required molecular weight range of 2000-4000. The principle behind this method for controlling crystal size is as follows: The solvent and aqueous phases mix to form an oil-in-water emulsion. During the diffusion of the solvent into the aqueous phase due to its water solubility, the active ingredient becomes supersaturated and precipitates out. Two crystal-controlling substances, due to their amphiphilic nature, spontaneously deposit at the oil-water interface. Simultaneously, conformational changes and cross-linking occur due to the aggregation effects of non-covalent bonds such as hydrophobic bonds, π-π conjugation, and hydrogen bonds, forming hydrophobic spaces that are firmly adsorbed onto the crystal surface, controlling crystal growth. Furthermore, during aggregation, the negatively charged groups such as sulfonic acid groups, carboxyl groups, and hydroxyl groups in the two crystal-controlling agents face towards the aqueous phase, forming a diffuse electric double layer that prevents particle aggregation, thus controlling crystal size. Experiments demonstrate that the degree of sulfonation and molecular weight of crystal-controlling regulator B, along with the structure and molecular weight of crystal-controlling polymer C, have a crucial impact on particle size and stability, and the two exhibit a synergistic effect.

[0011] As described above, the reverse processing technology for pesticide suspensions controls the particle size and stability of the suspension by adjusting the stirring or shearing power during mixing. Several methods can be used when mixing the solvent and antisolvent phases. Firstly, adding the oil phase to the aqueous phase is called the reverse addition method; adding the aqueous phase to the oil phase is called the forward addition method. The different addition methods significantly affect the uniformity, stability, and particle size uniformity of the suspension. In the reverse addition method, the precipitated particles are too fast and difficult to control. Conversely, in the forward addition method, the precipitated particles are slower, easier to control, and have a more uniform particle size. Therefore, the forward addition method is preferred for better particle control. When using the reverse addition method, to obtain micron-sized suspensions, a stirring mixing process can be chosen, with the stirring power controlled at 400-1000 rpm; to obtain nano-sized particles, a shearing mixing process can be chosen, with the shearing power controlled at 5000-15000 rpm. When selecting the positive addition method, to obtain micron-sized suspensions, a stirring mixing process can be chosen, with the stirring power controlled at 600-1000 rpm; to obtain nano-sized suspensions, a shearing process can be chosen, with the shearing power controlled at 10000-15000 rpm.

[0012] As described above, the reverse processing technology for pesticide suspensions regulates the morphology and size of particles and their uniformity in the suspension by controlling the rate at which the antisolvent phase or solvent phase is added during mixing. The rate of addition has a certain impact on the particle size uniformity and precipitation effect of the suspension processed by this process. The addition rate should be controlled at 60-120 parts / minute (one part is 1% of the system), and the total addition time should be controlled at 50-100 seconds to make the particles more uniform. At the same time, the temperature needs to be controlled between 15-50°C.

[0013] The pesticide suspension reverse processing technology described above obtains stable suspension products by selecting a suitable thickening system. Suitable thickeners include one or more of magnesium aluminum silicate, organobentonite, xanthan gum, carboxymethyl cellulose, and gum arabic.

[0014] Compared with the prior art, the advantages and positive effects of the present invention are as follows:

[0015] The process of this invention uses a "bottom-up" method to control the size of the active ingredient crystals, avoiding the high-energy-consuming grinding process used in conventional suspension production, improving production efficiency and reducing production energy consumption. It is a reverse processing technology for pesticide suspensions with dissolution-emulsification-crystallization as the core process.

[0016] Compared with conventional grinding methods, this invention can reduce the time required to produce each ton of product by 1 / 3 to 1 / 2 and reduce energy consumption by 30-50%, thereby improving production efficiency and significantly reducing energy consumption. Detailed Implementation

[0017] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described below with reference to specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0018] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways than those described herein. Therefore, the invention is not limited to the specific embodiments disclosed in the following specification. Unless otherwise specified, all percentages of materials mentioned in the following embodiments are percentages by mass.

[0019] Example 1

[0020] In this embodiment, the mass fractions of each material are as follows: 95% emamectin benzoate (emamectin benzoate) TC: 2.42%; solvent: 10%, of which anhydrous ethanol is 6% and xylene is 4%; fatty alcohol block polyether: 3%; lignin sulfonate (molecular weight 10000, sulfonation degree 0.8): 3%; styrene acrylate polyoxyethylene ether polymer (molecular weight 3000): 2%; ethylene glycol: 2%; xanthan gum: 0.2%; water: 77.38%, of which 69.38% is used for the preparation of the antisolvent phase in the second step, and 8% of water is reserved for the swelling and thickening system in the fourth step.

[0021] The preparation process is as follows:

[0022] The first step is to weigh out the technical grade of abamectin, add xylene and anhydrous ethanol to dissolve it, and then add fatty alcohol block polyether to obtain the solvent phase.

[0023] The second step involves weighing water, adding lignin sulfonate (molecular weight 10000, sulfonation degree 0.8), and then adding styrene-acrylic acid polyoxyethylene ether polymer (molecular weight 3000) to dissolve and obtain the antisolvent phase.

[0024] The third step involves adding the antisolvent phase to the solvent phase at a rate of 90 parts per minute (one part being 1% of the system) while maintaining a stirring power of 600 rpm. After mixing, continue stirring at the same stirring rate for 15 minutes to obtain the suspension system.

[0025] The fourth step involves preparing a thickening system using xanthan gum, ethylene glycol, and reserved water. While shearing the suspension system at 10,000 rpm, the swollen thickening system is slowly added. After addition, shearing continues for 5 minutes at the same power to obtain D. 50 and D 90 The suspensions are 1.12µm and 2.34µm in size, respectively.

[0026] The suspension prepared in this embodiment was tested, and the results are shown in Table 1.

[0027] Table 1. Characterization results of the suspension.

[0028]

[0029] Upon testing, the particle size index D of the suspension prepared in this embodiment was found to be [missing information - likely a particle size distribution]. 50 and D 90 The particle size index D remains at 1.31 μm and 2.42 μm after storage at 0°C for 7 days. 50 and D 90 The values ​​remain at 1.12 μm and 2.13 μm, which meet the requirements for pesticide suspension concentrates.

[0030] Example 2

[0031] The formulation and dosage ratios in this embodiment are consistent with those in Example 1. 2.42% of abamectin technical grade was weighed and dissolved in xylene and anhydrous ethanol. Then, fatty alcohol block polyether was added to obtain the solvent phase. Water was weighed, and lignin sulfonate (molecular weight 10000, sulfonation degree 0.8) was added, followed by styrene-acrylate polyoxyethylene ether polymer, which was dissolved to obtain the antisolvent phase. At a shear power of 10000 rpm, the antisolvent phase was added to the solvent phase at a rate of 90 parts / minute (one part being 1% of the system weight). After mixing, stirring was continued for 15 minutes to obtain the suspension system. A thickening system was prepared using xanthan gum, ethylene glycol, and reserved water. While shearing the suspension system at 10000 rpm, the swollen thickening system was slowly added. After the addition was complete, shearing continued for 5 minutes to obtain D. 50 and D 90 The suspensions have diameters of 0.22 μm and 0.91 μm, respectively.

[0032] The characterization results of this embodiment are shown in Table 2.

[0033] Table 2. Characterization results of the suspension in Example 2

[0034]

[0035] Testing revealed that the particle size index D of the suspension obtained in this embodiment was [missing information - likely a value or indicator]. 50 and D 90 The particle size index D remains at 0.31 μm and 0.94 μm after storage at 0°C for 7 days. 50 and D 90 The values ​​remained at 0.25 μm and 0.84 μm, and other test items met the standards for pesticide suspension concentrates.

[0036] Examples 1 and 2 demonstrate that by altering the mixing process of the solvent and antisolvent phases, micron- or nano-sized suspensions can be prepared. Stable micron-sized suspensions can be obtained under stirring conditions within a suitable power range, while stable nano-sized suspensions can be obtained under shearing conditions.

[0037] Example 3

[0038] In this embodiment, the mass fractions of each material are as follows: 94% abamectin TC: 3.19%; solvent: 10% (specific content as shown in Table 3); fatty alcohol block polyether: 3%; lignin sulfonate (molecular weight 10000, sulfonation degree 0.8): 3%; styrene acrylate polyoxyethylene ether polymer (molecular weight 3000): 2%; ethylene glycol: 2%; xanthan gum: 0.2%; water: 76.61%.

[0039] Weigh out the technical grade of avermectin, add a solvent to dissolve the technical grade, and then add fatty alcohol block polyether to obtain the solvent phase; weigh out water, add lignin sulfonate (molecular weight 10000, degree of sulfonation 0.8), and then add styrene acrylate polyoxyethylene ether polymer (molecular weight 3000) to obtain the antisolvent phase; with a stirring power of 600 rpm, add the antisolvent phase to the solvent phase at a rate of 90 parts / minute (one part is 1% of the system), mix and continue stirring for 15 minutes to obtain the suspension system; prepare a thickening system with xanthan gum, ethylene glycol and reserved water, and slowly add the swollen thickening system while shearing the suspension system at 10000 rpm, and continue shearing for 5 minutes after the addition is complete to obtain the target suspension.

[0040] Table 3. Detection results of suspension in Example 3

[0041]

[0042] Table 3 shows that by compounding methanol and cyclohexanone solvents, D can be obtained when the methanol:cyclohexanone ratio is 4:6. 50 and D 90 The suspensions, with particle sizes of 1.12 μm and 2.32 μm respectively, exhibited narrow particle size distributions and good storage stability. Testing revealed that after 14 days of heat storage, the particle size index D of these suspensions... 50 and D 90 The particle size index D was 1.21 μm and 2.52 μm after storage at 0°C for 7 days. 50 and D 90 The values ​​remain at 1.12 μm and 2.24 μm, which meet the standards for pesticide suspension concentrates.

[0043] Example 4

[0044] In this embodiment, the mass fractions of each material are as follows: 94% avermectin technical grade: 3.19%; solvent: 10%, including 4% methanol and 6% cyclohexanone; fatty alcohol block polyether: 3%; lignin sulfonate (molecular weight 10000, sulfonation degree 0.8): 3%; styrene-acrylate polyoxyethylene ether polymer (molecular weight 3000): 2%; ethylene glycol: 2%; xanthan gum: 0.2%; water: 76.61%.

[0045] Weigh out avermectin technical grade, dissolve it in methanol and cyclohexanone solvents, then add fatty alcohol block polyether to obtain the solvent phase; weigh out water, add lignin sulfonate (molecular weight 10000, sulfonation degree 0.8), then add styrene-acrylate polyoxyethylene ether polymer (molecular weight 3000) to obtain the antisolvent phase; add the antisolvent phase to the solvent phase at a rate of 90 parts / min (one part is 1% of the system) while shearing at 10000 rpm, mix and continue stirring for 15 minutes to obtain the suspension system; prepare a thickening system with xanthan gum, ethylene glycol, and reserved water, and slowly add the swollen thickening system while shearing the suspension system at 10000 rpm, continue shearing for 5 minutes after addition to obtain D. 50 and D 90 The target suspending agents are 0.52 μm and 0.71 μm, respectively.

[0046] Testing revealed that the particle size index D of the suspension after storage at 54°C for 14 days was... 50 and D 90 The particle size index D was 0.43 μm and 0.73 μm after storage at 0°C for 7 days. 50 and D 90 The values ​​remain at 0.47 μm and 0.81 μm, which meet the standards for pesticide suspension concentrates.

[0047] Example 5

[0048] In this embodiment, the mass fractions of each material are as follows: 97% high-efficiency cyhalothrin: 2.58%; solvent: 10%, of which the mass ratio of cyclohexanone to xylene is 8:2; fatty alcohol block polyether: 3%; lignin sulfonate (molecular weight 10000, sulfonation degree 0.8): 3%; styrene-acrylic acid polyoxyethylene ether polymer (molecular weight 3000): 2%; ethylene glycol: 2%; xanthan gum: 0.2%; water: 77.22%.

[0049] Weigh out the technical grade of high-efficiency cyhalothrin, add a solvent to dissolve the technical grade, and then add fatty alcohol block polyether to obtain the solvent phase; weigh out water, add lignin sulfonate (molecular weight 10000, sulfonation degree 0.8), and then add styrene-acrylic acid polyoxyethylene ether polymer (molecular weight 3000) to obtain the antisolvent phase; with a stirring power of 600 rpm, add the antisolvent phase to the solvent phase at a rate of 90 parts / minute (one part is 1% of the system), mix, and continue stirring for 15 minutes to obtain the suspension system; prepare a thickening system with xanthan gum, ethylene glycol, and reserved water, and slowly add the swollen thickening system while shearing the suspension system at 10000 rpm, and continue shearing for 5 minutes after the addition is complete to obtain the target suspension D. 50 and D 90The particle sizes were 1.13 μm and 3.22 μm, respectively, exhibiting a narrow particle size distribution and good storage stability. After storage at 54°C for 14 days, the particle size index D... 50 and D 90 The particle size index D remains at 1.23 μm and 3.24 μm after 7 days of storage at 0°C. 50 and D 90 The values ​​remain at 1.21 μm and 3.13 μm, which meet the standards for pesticide suspension concentrates.

[0050] Example 6

[0051] In this embodiment, the mass fractions of each material are as follows: high-efficiency cyhalothrin: 2.58%; solvent: 10%, wherein the mass ratio of cyclohexanone to xylene is 8:2; fatty alcohol block polyether: 3%; lignin sulfonate (molecular weight 10000, sulfonation degree 0.8): 3%; styrene-acrylic acid polyoxyethylene ether polymer (molecular weight 3000): 2%; ethylene glycol: 2%; xanthan gum: 0.2%; water: 77.22%.

[0052] Weigh out the technical grade of high-efficiency cyhalothrin, dissolve it in cyclohexanone and xylene solvents, then add fatty alcohol block polyether to obtain the solvent phase; weigh out water, add lignin sulfonate, then add styrene-acrylate polyoxyethylene ether polymer, dissolve to obtain the antisolvent phase; add the antisolvent phase (1% of the system weight), mix and continue stirring for 15 minutes to obtain the suspension system; prepare a thickening system with xanthan gum, ethylene glycol, and reserved water, and slowly add the swollen thickening system while shearing the suspension system at 10000 rpm, continue shearing for 5 minutes after addition to obtain D. 50 and D 90 The target suspending agents have particle sizes of 0.45 μm and 0.67 μm, respectively.

[0053] Testing revealed that the particle size index D of the suspension concentrate decreased after storage at 54°C for 14 days. 50 and D 90 The particle size index D remains at 0.47 μm and 0.70 μm after storage at 0°C for 7 days. 50 and D 90 The values ​​remain at 0.46 μm and 0.68 μm, which meet the standards for pesticide suspension concentrates.

[0054] Comparative Example 1

[0055] In this comparative example, the molecular weight of the lignin sulfonate was 4300, the degree of sulfonation was 0.8, and the amount added accounted for 3% of the total mass of the material. The composition and content of the remaining substances and the preparation process were the same as in Example 1. The resulting suspension product D was obtained. 50 and D 90 The corresponding sizes are 5.21 μm and 32.53 μm, respectively.

[0056] Comparative Example 2

[0057] In this comparative example, the molecular weight of the lignin sulfonate was 16000, the degree of sulfonation was 0.8, and the amount added accounted for 3% of the total mass of the material. The composition and content of the remaining substances and the preparation process were the same as in Example 1. The resulting suspension product D was obtained. 50 and D 90 The corresponding sizes are 3.23 μm and 25.54 μm, respectively.

[0058] Comparative Examples 1 and 2 show that adding lignin sulfonates with molecular weights that are too low (less than 8000) or too high (greater than 12000) results in uneven particle size distribution in the prepared suspension, causing the formulation to separate and the drug to precipitate.

[0059] Comparative Example 3

[0060] In this comparative example, the molecular weight of the lignin sulfonate was 11000, the degree of sulfonation was 1.8, and the amount added accounted for 3% of the total mass of the material. The composition and content of the remaining substances and the preparation process were the same as in Example 1. The resulting suspension product D was obtained. 50 and D 90 The thicknesses are 2.55 μm and 17.59 μm, respectively.

[0061] Comparative Example 4

[0062] In this comparative example, the molecular weight of the lignin sulfonate was 10,000, the degree of sulfonation was 0.7, and the amount added accounted for 3% of the total mass of the material. The composition and content of the remaining substances and the preparation process were the same as in Example 1. The resulting suspension product D was obtained. 50 and D 90 The thicknesses are 6.81 μm and 27.82 μm, respectively.

[0063] Comparative Examples 3 and 4 revealed that adding too much (greater than 1.5) or too little (less than 0.8) sulfonate resulted in uneven particle size distribution in the prepared suspension, which easily led to stratification and drug crystal growth.

[0064] Comparative Example 5

[0065] In this comparative example, the lignin sulfonate had a molecular weight of 10,000 and a sulfonation degree of 0.8, and was added at 3% of the total mass of the materials. The carboxylate copolymer had a molecular weight of 1,500 and was added at 2% of the total mass of the materials. The composition of the remaining materials and the preparation process were the same as in Example 1, resulting in suspension product D. 50 and D 90 The thicknesses are 4.81 μm and 15.85 μm, respectively.

[0066] Comparative Example 6

[0067] In this comparative example, the lignin sulfonate had a molecular weight of 10,000 and a sulfonation degree of 0.8, and was added at 3% of the total mass of the materials. The carboxylate copolymer had a molecular weight of 5,000 and was added at 2% of the total mass of the materials. The composition of the remaining materials and the preparation process were the same as in Example 1, and the resulting suspension product D was obtained. 50 and D 90 The corresponding sizes are 5.63 μm and 23.24 μm, respectively.

[0068] According to Comparative Examples 5 and 6, adding carboxylate copolymers with excessively high molecular weight (greater than 4000) or excessively low molecular weight (less than 2000) results in uneven particle size distribution in the prepared suspension, which easily leads to stratification and drug crystal growth.

[0069] Comparative Example 7

[0070] This comparative example changed the amount of anhydrous ethanol and xylene, and did not add carboxylate copolymers. The other conditions were the same as in Example 1. The particle size detection results of the obtained suspension particles are shown in Table 4 below.

[0071] Table 4. Detection results of suspension particles

[0072]

[0073] By compounding anhydrous ethanol and xylene, it was found that when the ratio of anhydrous ethanol to xylene is 6:4, D can be obtained. 50 and D 90 The suspending agents with particle sizes of 1.51 μm and 3.23 μm, respectively, exhibited narrow particle size distributions and good performance. Furthermore, without the addition of carboxylate copolymers, the optimal particle size index D was observed after 14 days of storage at 54°C. 50 and D 90 The particle sizes increased to 6.43µm and 19.63µm respectively, which does not meet the application requirements of pesticide suspensions; their storage stability is poor, and the particle size increased significantly with the increase of storage time.

[0074] Comparative Example 8

[0075] This comparative example changed the ratio of crystal control regulator B (lignin sulfonate) and crystal control polymer C (carboxylate copolymer) in the formulation, and controlled the total ratio of the two to 5%. The other conditions were the same as in Example 1. Table 5 below shows the test data.

[0076] Table 5. Detection results of Comparative Example 8

[0077]

[0078] The above conclusions were obtained by adding crystal-controlled polymer C and screening the addition ratio between crystal-controlled regulator B and crystal-controlled polymer C. It was found that the effect was better when the ratio of crystal-controlled regulator B to crystal-controlled polymer C was 8:2 and 6:4, and the particle size distribution range was narrower when the ratio was 6:4.

[0079] Case study to verify the effectiveness.

[0080] Effect Verification Case 1

[0081] Target pest: Diamondback moth.

[0082] Crop: Cabbage.

[0083] Test reagent and application method: 2.3% abamectin SC (Examples 1 and 2), 10 ml / acre, spray.

[0084] Comparative agent and application method: 2.3% abamectin SC (prepared by grinding method), 10 ml / acre, spray.

[0085] The results are shown in Table 6.

[0086] Table 6. Results of effect verification.

[0087]

[0088] Effect Verification Case 2

[0089] Target pest: root-knot nematodes.

[0090] Crop: Cucumber.

[0091] Experiment location: Plant Protection Experiment Station, Shandong Agricultural University.

[0092] Test reagent and application method: 3% abamectin SC (example), 1000ml / mu, mixed with soil for application.

[0093] Comparative agent and application method: 3% abamectin SC is prepared by grinding, 1000ml / acre, and mixed into the soil for application.

[0094] The results are shown in Table 7.

[0095] Table 7. Results of effect verification.

[0096]

[0097] Effect Verification Case 3

[0098] Target pest: cabbage caterpillar.

[0099] Crop: Cabbage.

[0100] Experiment location: Plant Protection Experiment Station, Shandong Agricultural University.

[0101] Application method and usage: 2.5% high-efficiency cyhalothrin SC (example), 35ml / acre, spray.

[0102] Comparative agent and application method: 2.5% high-efficiency cyhalothrin SC (prepared by grinding method), 35ml / acre, spray.

[0103] The results are shown in Table 8.

[0104] Table 8 shows the results of the effect verification.

[0105]

[0106] This invention patent addresses the low efficiency and high energy consumption issues in conventional suspension processing. It develops a suspension method that, by adding suitable solvents, surfactants, and crystal-regulating substances, allows the crystal-regulating substances to firmly adsorb onto the surface of the precipitated crystals after drug crystal formation, controlling crystal growth and resulting in a stable target particle size. Research has revealed a synergistic effect between the formulation components and the processing technology, requiring creative effort to find the optimal combination of these factors. Performance verification shows that the micron-sized suspension prepared by this process has comparable efficacy to suspensions prepared using conventional grinding methods, while the nano-sized suspension prepared by this process has slightly higher efficacy than that prepared by grinding methods.

[0107] In summary, this invention provides a method for producing pesticide suspensions. The process is simple, the particle size is adjustable, and compared with conventional grinding methods, the production time per ton of product can be shortened by 1 / 3 to 1 / 2, and the energy consumption can be reduced by 30-50%, thereby improving production efficiency and significantly reducing energy consumption.

[0108] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments for application in other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A reverse processing technology for pesticide suspension concentrates, characterized in that, Obtained using any of the following methods: The first type: The mass fractions of each substance are as follows: 95% emamectin benzoate TC: 2.42%; solvent: 10%, of which anhydrous ethanol is 6% and xylene is 4%; fatty alcohol block polyether: 3%; lignin sulfonate with a molecular weight of 10000 and a sulfonation degree of 0.8: 3%; styrene-acrylate polyoxyethylene ether polymer with a molecular weight of 3000: 2%; ethylene glycol: 2%. Xanthan gum: 0.2%; Water: 77.38%, of which 69.38% is used to prepare the antisolvent phase, and 8% is reserved for swelling and thickening system; The preparation process is as follows: (1) Weigh 95% emamectin benzoate TC technical grade, add xylene solvent and anhydrous ethanol solvent to dissolve it, and then add fatty alcohol block polyether to obtain the solvent phase; (2) Weigh water, add lignin sulfonate, and then add styrene acrylic polyoxyethylene ether polymer to dissolve and obtain the antisolvent phase; (3) Based on a stirring power of 600 rpm, add the antisolvent phase to the solvent phase at a rate of 90 parts / minute, taking one part as 1% of the system mass fraction. After mixing, continue stirring at the same stirring rate for 15 minutes to obtain the suspension system. (4) Prepare a thickening system with xanthan gum, ethylene glycol and reserved water, and slowly add the swollen thickening system while shearing the suspension system at 10,000 rpm. After adding the thickening system, continue shearing for 5 minutes at the same power to obtain the suspension. The second type: The dosage of each substance is the same as in the first formulation. Weigh 95% emamectin benzoate TC technical grade, add xylene and anhydrous ethanol solvent to dissolve it, and then add fatty alcohol block polyether to obtain the solvent phase. Weigh water, add lignin sulfonate, and then add styrene acrylate polyoxyethylene ether polymer to dissolve and obtain the antisolvent phase. Based on a shear power of 10000 rpm, add the antisolvent phase to the solvent phase at a rate of 90 parts / minute, mix and continue stirring for 15 minutes to obtain the suspension system. Prepare a thickening system with xanthan gum, ethylene glycol and reserved water, and slowly add the swollen thickening system while shearing the suspension system at 10000 rpm, and continue shearing for 5 minutes to obtain the suspension.

2. A reverse processing technology for pesticide suspension concentrates, characterized in that, The mass fractions of each material are as follows: 94% abamectin TC: 3.19%; solvent: 10%; fatty alcohol block polyether: 3%; lignin sulfonate with a molecular weight of 10000 and a sulfonation degree of 0.8: 3%; styrene-acrylate polyoxyethylene ether polymer with a molecular weight of 3000: 2%; ethylene glycol: 2%. Xanthan gum: 0.2%, water: 76.61%; The solvent is methanol and cyclohexanone, wherein the mass ratio of methanol to cyclohexanone is 4:6; The preparation steps are as follows: Weigh 94% avermectin TC technical grade, add solvent to dissolve the technical grade, and then add fatty alcohol block polyether to obtain the solvent phase; weigh water, add lignin sulfonate, and then add styrene acrylate polyoxyethylene ether polymer to obtain the antisolvent phase; with a stirring power of 600 rpm, add the antisolvent phase to the solvent phase at a rate of 90 parts / minute, mix, and continue stirring for 15 minutes to obtain the suspension system; prepare a thickening system with xanthan gum, ethylene glycol, and reserved water, and slowly add the swollen thickening system while shearing the suspension system at 10000 rpm, and continue shearing for 5 minutes after the addition is complete to obtain the target suspension.

3. A reverse processing technology for pesticide suspension concentrates, characterized in that, The mass fractions of each material are as follows: 94% avermectin technical grade: 3.19%; solvent: 10%, including 4% methanol and 6% cyclohexanone; fatty alcohol block polyether: 3%; lignin sulfonate with a molecular weight of 10000 and a sulfonation degree of 0.8: 3%; styrene-acrylate polyoxyethylene ether polymer with a molecular weight of 3000: 2%; ethylene glycol: 2%. Xanthan gum: 0.2%, water: 76.61%; Weigh 94% avermectin technical grade, add methanol and cyclohexanone solvent to dissolve the technical grade, then add fatty alcohol block polyether to obtain the solvent phase; weigh water, add lignin sulfonate, then add styrene acrylate polyoxyethylene ether polymer, and dissolve to obtain the antisolvent phase; based on a shear power of 10000 rpm, add the antisolvent phase to the solvent phase at a rate of 90 parts / min, mix and continue stirring for 15 minutes to obtain the suspension system; prepare a thickening system with xanthan gum, ethylene glycol and reserved water, and slowly add the swollen thickening system while shearing the suspension system at 10000 rpm, continue shearing for 5 minutes after addition to obtain the target suspension.

4. A reverse processing technology for pesticide suspension concentrates, characterized in that, The mass fractions of each material are as follows: 97% high-efficiency cyhalothrin: 2.58%; solvent: 10%, of which cyclohexanone:xylene mass ratio is 8:2; fatty alcohol block polyether: 3%; lignin sulfonate with molecular weight 10000 and sulfonation degree 0.8: 3%; styrene-acrylic acid polyoxyethylene ether polymer with molecular weight 3000: 2%; ethylene glycol: 2%. Xanthan gum: 0.2%, water: 77.22%; Weigh out 97% high-efficiency cyhalothrin technical grade, add solvent to dissolve the technical grade, and then add fatty alcohol block polyether to obtain the solvent phase; weigh out water, add lignin sulfonate, and then add styrene acrylate polyoxyethylene ether polymer to obtain the antisolvent phase; with a stirring power of 600 rpm, add the antisolvent phase to the solvent phase at a rate of 90 parts / minute, mix and continue stirring for 15 minutes to obtain the suspension system; prepare a thickening system with xanthan gum, ethylene glycol and reserved water, and slowly add the swollen thickening system while shearing the suspension system at 10000 rpm, and continue shearing for 5 minutes after the addition is complete to obtain the target suspension.

5. A reverse processing technology for pesticide suspension concentrates, characterized in that, The mass fractions of each material are as follows: High-efficiency cyhalothrin: 2.58%; Solvent: 10%, of which cyclohexanone:xylene mass ratio is 8:2; Fatty alcohol block polyether: 3%; Lignosulfonate with molecular weight 10000 and sulfonation degree 0.8: 3%; Styrene-acrylic acid polyoxyethylene ether polymer with molecular weight 3000: 2%; Ethylene glycol: 2%. Xanthan gum: 0.2%, water: 77.22%; Weigh out the technical grade of high-efficiency cyhalothrin, add cyclohexanone solvent and xylene solvent to dissolve it, then add fatty alcohol block polyether to obtain the solvent phase; weigh out water, add lignin sulfonate, then add styrene acrylate polyoxyethylene ether polymer, dissolve to obtain the antisolvent phase, and add the antisolvent phase at 1% of the system mass fraction; Continue stirring for 15 minutes to obtain the suspension system; prepare a thickening system with xanthan gum, ethylene glycol, and reserved water, and slowly add the swollen thickening system while shearing the suspension system at 10,000 rpm. After the addition is complete, continue shearing for 5 minutes to obtain the target suspension.

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