Wettable carbendazim powder and preparation method thereof
Through the combination of modified polyoxyethylene ether and sulfonated dispersant, the problem of calcified wet powder is solved, the suspension rate and bactericidal effect are improved, and the operation difficulty is simplified, and the stability and efficient use of calcified wet powder are achieved.
Patent Information
- Application Number
- CN202510507625.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-22
- Publication Date
- 2025-07-11
AI Technical Summary
The pyrophyte wet powder is prone to moisture absorption and agglomeration during use, affecting the use effect and increasing the difficulty of operation.
Using a combination of modified polyoxyethylene ether wetting agent and sulfonated dispersant, a firm anchoring layer is formed on the surface of the polyoxyethylene ether by modifying polyoxyethylene ether to reduce the liquid-solid interface tension, the sulfonated dispersant provides electrostatic repulsion to prevent agglomeration, while adding composite bactericides and auxiliary formulations to improve suspension rate and thermal storage stability.
Effectively inhibit the agglomeration of sterilized wet powder, improve the suspension rate and sterilization effect, reduce the stability of heat storage, and simplify the difficulty of operation.
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Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of pesticides, and particularly to a carbendazim wettable powder and a preparation method thereof. Background Art
[0002] The use of pesticides is crucial for protecting crops from pests and diseases. However, traditional pesticides are mostly single agents, with single effects, and long-term use easily leads to crop resistance, thereby reducing the control effect of pesticides. To address this issue, the pesticide industry has begun to explore the research and development of compound pesticides, that is, mixing multiple pesticide active ingredients according to a certain mixing ratio and compounding method to form new pesticide products. Such compound pesticides can not only improve the control effect, but also delay the crop resistance, reduce the amount of pesticides used, thereby reducing costs and mitigating the impact on the environment.
[0003] As a broad-spectrum fungicide, carbendazim is widely used in agricultural production. However, with the extension of its use time, the crop resistance to it is gradually increasing. To improve the control effect of carbendazim and delay the crop resistance, researchers have begun to try to compound carbendazim with other pesticide active ingredients to develop new compound pesticide products.
[0004] There are still some technical problems in the use of carbendazim wettable powder. Since carbendazim wettable powder is prone to moisture absorption and caking, this not only affects its use effect, but also increases the operation difficulty for users. Summary of the Invention
[0005] The purpose of the present invention is to provide a carbendazim wettable powder and a preparation method thereof to solve the following technical problems:
[0006] How to reduce the dilution caking property of carbendazim wettable powder during use.
[0007] The purpose of the present invention can be achieved by the following technical solutions:
[0008] In a first aspect, the present invention discloses a carbendazim wettable powder, which comprises the following components by weight: 65 - 75 parts of carbendazim; 4 - 10 parts of modified polyoxyethylene ether wetting agent; 6 - 15 parts of sulfonated dispersant; 3 - 12 parts of compound fungicide; 2 - 5 parts of auxiliary preparation;
[0009] Preferably, there are 70 parts of carbendazim; 7 parts of modified polyoxyethylene ether wetting agent; 8 parts of sulfonated dispersant; 5 parts of compound fungicide; and 3 parts of auxiliary preparation.
[0010] Further, the modified polyoxyethylene ether wetting agent is a graft copolymer of a polyoxyethylene ether segment and trimethylsiloxane. Through repeated experiments, it is determined that when its HLB value is 12 - 18 and the grafting rate is 20% - 35%, the effect is the best; the sulfonated dispersant is prepared by sulfonating a styrene - maleic anhydride copolymer. Through repeated experiments, it is determined that when its sulfonation degree is 0.8 - 1.5 mmol / g, the effect is the best;
[0011] Preferably, the HLB value of the modified polyoxyethylene ether wetting agent is 15 and the grafting rate is 30%; the sulfonation degree of the sulfonated dispersant is 1.2 mmol / g.
[0012] Further, the preparation method of the modified polyoxyethylene ether includes the following steps:
[0013] Step A1: Vacuum - dry the polyoxyethylene ether (PEG) and then mix it with anhydrous toluene. Then, heat it to 60°C, and drop - wise add trimethylchlorosilane and stir evenly to form a mixed solution. Drop - wise add a 20% NaOH aqueous solution to adjust the pH of the mixed solution to 8 - 9, and then heat it to 70 - 80°C and react for 6 h to obtain a reaction solution; among them, the molar ratio of the vacuum - dried polyoxyethylene ether to trimethylchlorosilane is 1:(0.2 - 0.6); under alkaline conditions, the hydroxyl group (-OH) in PEG undergoes a nucleophilic substitution reaction with trimethylchlorosilane (Cl - Si(CH3)3) to form a siloxane bond (-O - Si(CH3)3) and release HCl;
[0014] Step A2: Cool the reaction solution to 40°C, add deionized water and stir for 30 min, then filter and wash to obtain an organic phase. First, perform rotary evaporation on the organic phase at 60°C and - 0.09 MPa, and then perform distillation at 150°C and 1 Pa to obtain a light - yellow transparent liquid, which is the modified polyoxyethylene ether.
[0015] Further, in step A1, the method for vacuum - drying the polyoxyethylene ether is: Place the polyoxyethylene alcohol in a vacuum drying oven and dry it at 80°C and a vacuum degree of - 0.08 MPa for 2 h.
[0016] Further, in step A1, the water content of the vacuum - dried polyoxyethylene ether ≤0.1%; PEG contains hydrophilic hydroxyl groups. If the water is not removed, it will undergo a hydrolysis side reaction with trimethylchlorosilane to form silanol (Si - OH) instead of the target product. Therefore, dehydrating to a water content ≤0.1% can ensure the efficient progress of the silylation reaction.
[0017] Further, in step A1, the dosage ratio of the vacuum - dried polyoxyethylene ether to anhydrous toluene is 1 g:2 mL.
[0018] Further, in step A2, the added volume of deionized water is 25% of the volume of anhydrous toluene.
[0019] Further, in step A2, the method of filtration is: filtering using a separatory funnel; the method of washing is: successively washing with a 5% aqueous HCl solution to remove residual NaOH, washing with a saturated NaHCO3 solution to neutralize unreacted HCl and acidic by-products until neutral.
[0020] Based on this, a preferred preparation method of modified polyoxyethylene ether is obtained, including the following steps:
[0021] Step A1: Place polyoxyethylene ether in a vacuum drying oven, dry at 80 °C and a vacuum degree of -0.08 MPa for 2 h until the water content ≤ 0.1%, then mix it with anhydrous toluene according to a dosage ratio of 1 g:2 mL, then heat up to 60 °C, and then dropwise add trimethylchlorosilane and stir evenly to form a mixed solution. Dropwise add a 20% aqueous NaOH solution to adjust the pH of the mixed solution to 8.5, and then heat up to 75 °C and react for 6 h to obtain a reaction solution; wherein, the molar ratio of polyoxyethylene ether after vacuum drying to trimethylchlorosilane is 1:0.4;
[0022] Step A2: Cool the reaction solution to 40 °C, add deionized water accounting for 25% of the volume of anhydrous toluene and stir for 30 min, then filter using a separatory funnel, and wash the filter material successively with a 5% aqueous HCl solution and a saturated NaHCO3 solution until neutral to obtain an organic phase. Rotate evaporate the organic phase at 60 °C and -0.09 MPa first, and then distill at 150 °C and 1 Pa to obtain a light yellow transparent liquid, namely modified polyoxyethylene ether, with an HLB value of 15 and a grafting rate of 30%.
[0023] Further, the preparation method of the sulfonated dispersant includes the following steps:
[0024] Step B1: Mix styrene and maleic anhydride according to a molar ratio of 1:1, then add ammonium persulfate accounting for 0.5 wt% of the total mass and stir evenly, and then add them together into xylene to form a mixed solution with a solid content of 30%. React the mixed solution at 120 °C and 0.4 MPa for 8 h, add acetone to precipitate, and after vacuum drying, obtain a white powder;
[0025] Step B2: Dissolve the white powder in concentrated sulfuric acid at a temperature ≤ 10 °C, then add chlorosulfonic acid thereto, then heat up to 40 °C and stir and react for 3 - 5 h. Monitor the sulfonation degree by potentiometric titration and stop the reaction after reaching the target value. Pour the reaction solution into ice water to precipitate, and then filter and wash to obtain a sulfonated product;
[0026] Step B3: Dissolve the sulfonated product in deionized water, adjust the pH to 6.5 - 7.0, and then perform spray drying at an inlet temperature of 180 °C and an outlet temperature of 80 °C to obtain a light brown powder. After grinding and sieving, the sulfonated dispersant is obtained.
[0027] Furthermore, the added volume of acetone is 2 - 5 times that of the mixed solution.
[0028] Preferably, the added volume of acetone is 3 times that of the mixed solution.
[0029] Furthermore, the dosage ratio of the white powder to concentrated sulfuric acid is 1 g:10 mL, and the added volume of chlorosulfonic acid is 30% of that of concentrated sulfuric acid.
[0030] Based on this, a preferred preparation method of the sulfonated dispersant is obtained, including the following steps:
[0031] Step B1: Mix styrene and maleic anhydride in a molar ratio of 1:1, then add 0.5 wt% of ammonium persulfate based on the total mass and stir evenly. Then add them together into xylene to form a mixed solution with a solid content of 30%. React the mixed solution at 120 °C and 0.4 MPa for 8 h, add acetone with a volume 3 times that of the mixed solution for precipitation, and add the precipitate into a vacuum drying oven to dry at 120 °C and a vacuum degree of -0.08 MPa for 2 h to obtain a white powder; during this process, styrene (electron-rich monomer) and maleic anhydride (electron-deficient monomer) alternate polymerization through the charge transfer complex mechanism to form a strictly alternating structure (-St-MA-St-MA-); ammonium persulfate initiates the generation of sulfate radicals (SO4 - ), attacking the double bond of the monomer to initiate chain growth.
[0032] Step B2: Dissolve the white powder in concentrated sulfuric acid at a temperature ≤10 °C according to a dosage ratio of 1 g:10 mL, then add chlorosulfonic acid with a volume of 30% of that of concentrated sulfuric acid thereto, and then raise the temperature to 40 °C and stir and react for 4 h. Concentrated sulfuric acid serves as a solvent and a sulfonating agent, and the ortho / para positions of the benzene ring in the styrene unit are sulfonated to generate sulfonic acid groups (-SO3H); monitor the sulfonation degree by potentiometric titration, stop the reaction after reaching 1.2 mmol / g, pour the reaction solution into ice water to precipitate, then filter with a separatory funnel, and wash with clear water until neutral to obtain the sulfonated product.
[0033] Step B3: Dissolve the sulfonated product in deionized water to form a slurry with a solute mass fraction of 60%, then dropwise add a 10% aqueous NaOH solution to adjust the pH to 6.5, and use NaOH to neutralize the sulfonic acid group (-SO3H → -SO3 - Na +) It can enhance water solubility while avoiding the destruction of the pesticide active ingredient in an acidic environment; then spray drying is carried out at an inlet temperature of 180 °C and an outlet temperature of 80 °C to obtain a light brown powder. Quick drying is carried out to prevent the oxidation or hydrolysis of the sulfonic acid group and maintain the integrity of the molecular structure; after grinding by a grinder and passing through a 200-mesh sieve, the sulfonated dispersant is obtained.
[0034] Further, the compound bactericide is a composite system composed of at least two of pyraclostrobin, azoxystrobin, and fluazinam;
[0035] Preferably, the compound bactericide is a mixture composed of pyraclostrobin, azoxystrobin, and fluazinam in a weight ratio of 1:1:1.
[0036] Further, the auxiliary preparation contains a carrier and a stabilizer. The carrier is a composition composed of diatomite and nano kaolin in a ratio of 2:1, and the stabilizer is fumed silica.
[0037] In a second aspect, the present invention also discloses a preparation method of the carbendazim wettable powder as described above, including the following steps:
[0038] S1. Mix carbendazim with a modified polyoxyethylene ether wetting agent and then ball mill to obtain fine particles with a particle size D50 ≤ 5 μm;
[0039] S2. Mix the sulfonated dispersant and an ethanol aqueous solution in a volume ratio of 3:1 evenly to form a colloidal solution, and then coat it on the surface of the fine particles in a spray form to obtain sulfonated fine particles;
[0040] S3. Mix the auxiliary preparation with the sulfonated fine particles, then send them into a fluidized bed and mix them at an air flow rate of 8 - 12 m / s for 2 h. After taking them out, send them into a high-pressure homogenizer together with the compound bactericide and mix them evenly. Finally, carry out vacuum freeze-drying in a humidity environment with RH ≤ 20%, and the carbendazim wettable powder with a water content ≤ 0.8% is obtained.
[0041] Based on this, a preferred preparation method of the carbendazim wettable powder is obtained, including the following steps:
[0042] S1. Mix carbendazim with a modified polyoxyethylene ether wetting agent in proportion and then ball mill. Zirconia is selected as the grinding ball, the ball-to-material ratio is 15:1, and the ball milling time is 2 h to obtain fine particles with a particle size D50 ≤ 5 μm;
[0043] S2. Mix the sulfonated dispersant and an ethanol aqueous solution with a mass fraction of 70% in a volume ratio of 3:1 evenly to form a colloidal solution, and then use a spray drying tower to coat it on the surface of the fine particles in a spray form. The inlet temperature of the spray is 120 °C and the outlet temperature is 80 °C to obtain sulfonated fine particles;
[0044] S3. Mix the auxiliary preparation with the sulfonated particles, then send them into a fluidized bed and mix for 2 h at an air flow rate of 10 m / s. After taking them out, send them into a high-pressure homogenizer together with the compound bactericide to mix evenly. Finally, carry out vacuum freeze-drying in a humidity environment with RH ≤ 20%, and carbendazim wettable powder with water content ≤ 0.8% can be obtained.
[0045] Advantages of the present invention:
[0046] 1. The carbendazim wettable powder of the present invention is added with modified polyoxyethylene ether. During the preparation process of the modified polyoxyethylene ether, under alkaline conditions, the hydroxyl group (-OH) in PEG undergoes a nucleophilic substitution reaction with trimethylchlorosilane (Cl-Si(CH3)3) to form a siloxane bond (-O-Si(CH3)3) and release HCl. Among them, the siloxane chain segment (Si-CH3) adsorbs on the surface of the hydrophobic carbendazim particles, and a firm anchoring layer can be formed. The polyether chain segment stretches in water, reducing the liquid-solid interfacial tension and thus reducing the contact angle. The steric hindrance effect of the graft copolymer inhibits particle aggregation, thereby improving the suspension rate and inhibiting the caking and agglomeration of the carbendazim wettable powder.
[0047] 2. The carbendazim wettable powder of the present invention is added with a sulfonated dispersant. The ionization of the sulfonic acid group in the sulfonated dispersant gives the particle surface a strong negative charge, and agglomeration can be prevented through electrostatic repulsion. The main chain of the copolymer adsorbs on the particle surface, and the side chain sulfonic acid groups stretch outwards to form a hydration layer, improving the suspension rate. The ionic bonding of the sulfonic acid group and the amino group of the carrier fixes the active ingredient, so the thermal storage stability of the product can also be improved. Specific embodiments
[0048] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.
[0049] The experimental methods in the following embodiments are all conventional methods, unless otherwise specified, and are carried out according to the technologies or conditions described in the literature in this field or according to the product instructions. The materials, reagents, etc. used in the following embodiments can be obtained from commercial channels unless otherwise specified.
[0050] Preparation Example 1
[0051] Prepare modified polyoxyethylene ether:
[0052] Step 1: Place 100 g of polyoxyethylene ether in a vacuum drying oven and dry it at 80 °C and a vacuum degree of -0.08 MPa for 2 h. After taking it out, detect its moisture content to be 0.86%. Then take 60 g of the vacuum-dried polyoxyethylene ether (0.02 mol) and add it to a four-necked flask. Then add 120 mL of anhydrous toluene, and then heat it up to 60 °C. Then add 6.8 g of trimethylchlorosilane (0.05 mol) dropwise to the four-necked flask and shake it evenly to form a mixed solution. Dropwise add a 20% NaOH aqueous solution to adjust the pH of the mixed solution to 8.5, and then heat it up to 75 °C and react for 6 h to obtain a reaction solution.
[0053] Step 2: Cool the reaction solution to 40 °C, add 30 mL of deionized water and stir for 30 min. Then use a separatory funnel for filtration. The filter material is washed with a 5% HCl aqueous solution and a saturated NaHCO3 solution in sequence until it is neutral to obtain an organic phase. The organic phase is first subjected to rotary evaporation at 60 °C and -0.09 MPa, and then distilled at 150 °C and 1 Pa to obtain a light yellow transparent liquid, that is, modified polyoxyethylene ether. After detection, its HLB value is 15 and the grafting rate is 30%.
[0054] Preparation Example 2
[0055] Preparation of sulfonated dispersant:
[0056] Step 1: Add styrene and maleic anhydride in a molar ratio of 1:1 (a total of 86 g) to a beaker and mix evenly. Then add 0.43 g of ammonium persulfate and stir evenly. Then add 202 g of xylene to the beaker and stir evenly to form a mixed solution. Transfer the mixed solution to a high-pressure reactor and react at 120 °C and 0.4 MPa for 8 h. Add acetone with a volume three times that of the mixed solution for precipitation. The precipitate is added to a vacuum drying oven and dried at 120 °C and a vacuum degree of -0.08 MPa for 2 h to obtain 80.5 g of white powder.
[0057] Step 2: Dissolve 80 g of the white powder in 8001 mL of concentrated sulfuric acid (mass fraction 85%) at a temperature of 10 °C. Then add 240 mL of chlorosulfonic acid to it. Subsequently, heat it up to 40 °C and stir and react for 4 h. Monitor the sulfonation degree by potentiometric titration. After reaching 1.2 mmol / g, stop the reaction. Pour the reaction solution into ice water to precipitate, and then use a separatory funnel for filtration. Then wash it with clear water until it is neutral to obtain a sulfonated product.
[0058] Step 3: Dissolve the sulfonated product in deionized water to form a slurry with a solute mass fraction of 60%. Then dropwise add a 10% NaOH aqueous solution to adjust the pH to 6.5. Then carry out spray drying at an inlet temperature of 180 °C and an outlet temperature of 80 °C to obtain a light brown powder. After grinding with a grinder and passing through a 200-mesh sieve, the sulfonated dispersant is obtained.
[0059] Preparation Example 3
[0060] Compared with Preparation Example 2, the only difference is that in Step 2, the sulfonation degree was monitored by potentiometric titration and the reaction was stopped after reaching 0.8 mmol / g. The other steps and conditions were exactly the same, and finally a sulfonated dispersant was obtained.
[0061] Preparation Example 4
[0062] Compared with Preparation Example 2, the only difference is that in Step 2, the sulfonation degree was monitored by potentiometric titration and the reaction was stopped after reaching 1.5 mmol / g. The other steps and conditions were exactly the same, and finally a sulfonated dispersant was obtained.
[0063] Comparative Preparation Example 1
[0064] Prepare a dispersant:
[0065] Compared with Preparation Example 2, the only difference is that Steps 2 and 3 were cancelled, and the white powder obtained in Step 1 was directly used as the dispersant.
[0066] Example 1
[0067] Prepare carbendazim wettable powder:
[0068] Step 1: 70 g of carbendazim and 7 g of the modified polyoxyethylene ether wetting agent prepared in Preparation Example 1 were mixed and ball-milled. Zirconia was used as the grinding ball, the ball-to-material ratio was 15:1, and the ball-milling time was 2 h to obtain fine particles with a particle size D50 ≤ 5 μm;
[0069] Step 2: 8 g of the sulfonated dispersant prepared in Preparation Example 2 and an ethanol aqueous solution with a mass fraction of 70% were mixed evenly at a volume ratio of 3:1 to form a colloidal solution, and then it was coated on the surface of the fine particles in a spray form using a spray drying tower. The inlet air temperature of the spray was 120 °C and the outlet air temperature was 80 °C to obtain sulfonated fine particles;
[0070] Step 3: 1 g of diatomaceous earth, 0.5 g of nano kaolin, and 1.5 g of fumed silica were mixed with the sulfonated fine particles, and then they were sent to a fluidized bed and mixed at an air flow rate of 10 m / s for 2 h. After taking out, they were sent to a high-pressure homogenizer and mixed evenly with 1.7 g of pyraclostrobin, 1.7 g of azoxystrobin, and 1.7 g of fluazinam. Finally, vacuum freeze-drying was carried out in a humidity environment with RH ≤ 20% to obtain carbendazim wettable powder with a water content ≤ 0.8%.
[0071] Example 2
[0072] Prepare carbendazim wettable powder:
[0073] Step 1: 65 g of carbendazim and 4 g of the modified polyoxyethylene ether wetting agent prepared in Preparation Example 1 were mixed and ball-milled. Zirconia was used as the grinding ball, the ball-to-material ratio was 15:1, and the ball-milling time was 2 h to obtain fine particles with a particle size D50 ≤ 5 μm;
[0074] Step 2: Mix 6 g of the sulfonated dispersant prepared in Preparation Example 2 with an ethanol aqueous solution with a mass fraction of 70% in a volume ratio of 3:1 to form a colloidal solution. Then, use a spray drying tower to coat it on the surface of the microparticles in a spray form. The inlet air temperature of the spray is 120 °C and the outlet air temperature is 80 °C to obtain sulfonated microparticles.
[0075] Step 3: Mix 1 g of diatomaceous earth, 0.5 g of nano kaolin, and 0.5 g of fumed silica with the sulfonated microparticles, and then send them into a fluidized bed to mix for 2 h at an air flow rate of 10 m / s. After taking them out, send them into a high-pressure homogenizer together with 1 g of pyraclostrobin, 1 g of azoxystrobin, and 1 g of fluazinam to mix evenly. Finally, perform vacuum freeze-drying in a humidity environment with RH ≤ 20% to obtain carbendazim wettable powder with a moisture content ≤ 0.8%.
[0076] Example 3
[0077] Step 1: Mix 75 g of carbendazim with 10 g of the modified polyoxyethylene ether wetting agent prepared in Preparation Example 1 and then ball-mill them. The grinding balls are made of zirconia, the ball-to-material ratio is 15:1, and the ball-milling time is 2 h to obtain microparticles with a particle size D50 ≤ 5 μm.
[0078] Step 2: Mix 15 g of the sulfonated dispersant prepared in Preparation Example 2 with an ethanol aqueous solution with a mass fraction of 70% in a volume ratio of 3:1 to form a colloidal solution. Then, use a spray drying tower to coat it on the surface of the microparticles in a spray form. The inlet air temperature of the spray is 120 °C and the outlet air temperature is 80 °C to obtain sulfonated microparticles.
[0079] Step 3: Mix 3 g of diatomaceous earth, 1.5 g of nano kaolin, and 0.5 g of fumed silica with the sulfonated microparticles, and then send them into a fluidized bed to mix for 2 h at an air flow rate of 10 m / s. After taking them out, send them into a high-pressure homogenizer together with 3 g of pyraclostrobin, 3 g of azoxystrobin, and 3 g of fluazinam to mix evenly. Finally, perform vacuum freeze-drying in a humidity environment with RH ≤ 20% to obtain carbendazim wettable powder with a moisture content ≤ 0.8%.
[0080] Example 4
[0081] Prepare carbendazim wettable powder:
[0082] Compared with Example 1, the difference is only that: in Step 2, the sulfonated dispersant prepared in Preparation Example 2 is replaced with the sulfonated dispersant prepared in Preparation Example 3, and other steps and conditions remain the same, and finally carbendazim wettable powder is prepared.
[0083] Example 5
[0084] Prepare carbendazim wettable powder:
[0085] Compared with Example 1, the difference is only that: in Step 2, the sulfonated dispersant prepared in Preparation Example 2 is replaced with the sulfonated dispersant prepared in Preparation Example 4, and other steps and conditions remain the same, and finally carbendazim wettable powder is prepared.
[0086] Comparative Example 1
[0087] Prepare carbendazim wettable powder:
[0088] Compared with Example 1, the difference is only that: in Step 1, the modified polyoxyethylene ether wetting agent prepared in Preparation Example 1 is replaced with polyoxyethylene ether, and other steps and conditions remain the same, and finally carbendazim wettable powder is prepared.
[0089] Comparative Example 2
[0090] Prepare carbendazim wettable powder:
[0091] Compared with Example 1, the difference is only that: in Step 2, the sulfonated dispersant prepared in Preparation Example 2 is replaced with the dispersant prepared in Comparative Preparation Example 1, and other steps and conditions remain the same, and finally carbendazim wettable powder is prepared.
[0092] Comparative Example 3
[0093] Prepare carbendazim wettable powder:
[0094] Compared with Example 1, the difference is only that: in Step 2, the sulfonated dispersant prepared in Preparation Example 2 is replaced with DMF-6 dispersant (commonly used in the prior art), and other steps and conditions remain the same, and finally carbendazim wettable powder is prepared.
[0095] Comparative Example 4
[0096] Prepare carbendazim wettable powder:
[0097] Compared with Example 1, the difference is only that: in Step 1, the modified polyoxyethylene ether wetting agent prepared in Preparation Example 1 is replaced with polyoxyethylene ether; in Step 2, the sulfonated dispersant prepared in Preparation Example 2 is replaced with DMF-6 dispersant; other steps and conditions remain the same, and finally carbendazim wettable powder is prepared.
[0098] Perform performance tests on the carbendazim wettable powders prepared in Examples 1-5 and Comparative Examples 1-4, including their wetting time, suspension rate, thermal storage stability, and bactericidal rate. The test methods are as follows:
[0099] Wetting time (s): Refer to GB / T 5451-2001;
[0100] Suspension rate (%): Refer to CIPAC MT 184;
[0101] Thermal storage stability: Refer to FAO standard
[0102] The test results are listed in Table 1 as follows:
[0103] Table 1
[0104]
[0105]
[0106] By analyzing the data in Table 1, it can be seen that compared with Comparative Examples 1-4, the carbendazim wettable powder prepared in Examples 1-5 has significantly faster wetting time, higher suspension rate and qualified thermal storage stability, which indicates that the caking and agglomeration phenomena of the carbendazim wettable powder of the present invention have been greatly improved.
[0107] Next, the bactericidal rate of the carbendazim wettable powder prepared in Examples 1-5 and Comparative Examples 1-4 was tested. The test method refers to NY / T 1156-2006. The test results are listed in Table 2 as follows:
[0108]
[0109] By analyzing the data in Table 2, it can be known that compared with Comparative Examples 1-4, the carbendazim wettable powder prepared in Examples 1-5 has a significantly higher bactericidal rate, which indicates that the bactericidal effect of the carbendazim wettable powder of the present invention is stronger.
[0110] The above has described a specific embodiment of the present invention in detail, but the above content is only a preferred embodiment of the present invention and should not be considered as limiting the scope of implementation of the present invention. All equivalent changes and improvements made according to the scope of the application of the present invention should still fall within the scope covered by the patent of the present invention.
Claims
1. A carbendazim wettable powder, characterized in that, It comprises the following components by weight parts: Carbendazim 65 - 75 parts; Modified polyoxyethylene ether wetting agent 4 - 10 parts; Sulfonated dispersant 6 - 10 parts; Compound bactericide 3 - 8 parts; Auxiliary preparation 2 - 5 parts; Among them, the modified polyoxyethylene ether wetting agent is a graft copolymer of a polyoxyethylene ether segment and trimethylsiloxane, with an HLB value of 12 - 18 and a grafting rate of 20% - 35%; The sulfonated dispersant is prepared by sulfonation reaction of a styrene - maleic anhydride copolymer, with a sulfonation degree of 0.8 - 1.5 mmol / g.
2. The carbendazim wettable powder according to claim 1, wherein The preparation method of the modified polyoxyethylene ether comprises the following steps: Step A1: Vacuum - dry the polyoxyethylene ether and then mix it with anhydrous toluene, then raise the temperature to 60°C, and then dropwise add trimethylchlorosilane and stir evenly to form a mixed solution. Adjust the pH of the mixed solution to 8 - 9, and then raise the temperature to 70 - 80°C and react for 6 h to obtain a reaction solution; Among them, the molar ratio of the vacuum - dried polyoxyethylene ether to trimethylchlorosilane is 1:(0.2 - 0.6); Step A2: Cool the reaction solution to 40°C, add deionized water and stir for 30 min, then filter and wash to obtain an organic phase. First, perform rotary evaporation on the organic phase at 60°C and - 0.09 MPa, and then perform distillation at 150°C and 1 Pa to obtain a light - yellow transparent liquid, namely the modified polyoxyethylene ether.
3. The carbendazim wettable powder according to claim 2, wherein In step A1, the water content of the polyoxyethylene ether after vacuum drying is ≤0.1%.
4. The carbendazim wettable powder according to claim 2, wherein, In step A1, the dosage ratio of the vacuum - dried polyoxyethylene ether to anhydrous toluene is 1 g:2 mL; In step A2, the added volume of the deionized water is 25% of the anhydrous toluene.
5. The carbendazim wettable powder according to claim 1, wherein The preparation method of the sulfonated dispersant comprises the following steps: Step B1: Mix styrene and maleic anhydride according to a molar ratio of 1:1, then add ammonium persulfate accounting for 0.5 wt% of the total mass and stir evenly, and then add them together into xylene to form a mixed solution with a solid content of 30%. React the mixed solution at 120°C and 0.4 MPa for 8 h, add acetone to precipitate, and after vacuum drying, obtain a white powder; Step B2: Dissolve the white powder in concentrated sulfuric acid with a temperature ≤10°C, then add chlorosulfonic acid to it, then raise the temperature to 40°C and stir and react for 3 - 5 h. Monitor the sulfonation degree by potentiometric titration, stop the reaction after reaching the target value, pour the reaction solution into ice water to precipitate, and then filter and wash to obtain a sulfonated product; Step B3: Dissolve the sulfonated product in deionized water, adjust the pH to 6.5 - 7.0, and then perform spray drying at an inlet temperature of 180°C and an outlet temperature of 80°C to obtain a light - brown powder. After grinding and sieving, the sulfonated dispersant is obtained.
6. The carbendazim wettable powder according to claim 5, wherein, In step B1, the added volume of the acetone is 2 - 5 times that of the mixed solution.
7. The carbendazim wettable powder according to claim 5, characterized in that, In step B2, the dosage ratio of the white powder to concentrated sulfuric acid is 1 g:10 mL, and the added volume of the chlorosulfonic acid is 30% of the concentrated sulfuric acid.
8. The carbendazim wettable powder according to claim 1, wherein The compound bactericide is a composite system composed of at least two of pyraclostrobin, azoxystrobin, and fluazinam.
9. The carbendazim wettable powder according to claim 1, characterized in that, The auxiliary preparation contains a carrier and a stabilizer. The carrier is a composition composed of diatomite and nano kaolin in a ratio of 2:1, and the stabilizer is fumed silica.
10. A preparation method of carbendazim wettable powder according to any one of claims 1-9, characterized in that, It includes the following steps: S1. Mix carbendazim with a modified polyoxyethylene ether wetting agent and then ball-mill to obtain fine particles with a particle size D50 ≤ 5 μm. S2. Mix a sulfonated dispersant with an ethanol aqueous solution in a volume ratio of 3:1 to form a colloidal solution, and then coat the surface of the fine particles in a spray form to obtain sulfonated fine particles. S3. Mix the auxiliary preparation with the sulfonated fine particles, then send them into a fluidized bed and mix for 2 h at an air flow rate of 8 - 12 m / s. After taking out, send them into a high-pressure homogenizer together with a compound fungicide and mix evenly. Finally, carry out vacuum freeze-drying in a humidity environment with RH ≤ 20%, and the wettable powder of carbendazim with a moisture content ≤ 0.8% can be obtained.