Suspending agent containing trifluoropyridylamine and fosthiazate and preparation method thereof

Abstract

The invention discloses a suspending agent containing trifluoropyridylamine and fosthiazate and a preparation method of the suspending agent, and belongs to the technical field of pesticides. A self-synthesized specific suspension system is introduced, an excellent network structure and interface activity can be formed, the suspension system is more stable, the suspension system and a composite dispersing agent (fatty alcohol-polyoxyethylene ether phosphate and maleic anhydride-polystyrene copolymer) with a specific ratio have a synergistic effect, the suspension rate and the dispersity are excellent, and the dispersion performance is good. The two different raw medicines are more stable in the storage process. Besides, the trifluoropyridinamine and the fosthiazate are compounded and prepared into the suspending agent, the two active components with different action mechanisms can be released and distributed in rhizosphere soil or crop disease infection sites more synchronously and more enduringly after being applied, the disease control effect generated by compounding the components is obviously superior to that of each single agent and simple physical mixing of the two agents, the control spectrum is effectively widened, and the control effect is obvious. The preparation technology is simple, industrial production is easy, and the whole processing technology is stable.

Description

Technical Field

[0001] This invention relates to the field of pesticide technology, and more specifically, to a suspension containing trifluoropyridineamine and thiazophosphonium and its preparation method. Background Technology

[0002] Pesticide suspensions are highly dispersed and stable suspensions formed by wet grinding of solid active ingredients that are insoluble or slightly soluble in water, with the aid of adjuvants. Because they use water as a matrix, they offer advantages such as environmental friendliness, safe production and use, low risk of phytotoxicity, and ease of tank mixing, making them an important development direction for modern pesticide formulations.

[0003] Trifluoropyridamole is a novel pyridine amide fungicide primarily used to control oomycete diseases such as downy mildew and late blight. It features good systemic conductivity, a unique mechanism of action, and safety for the environment and non-target organisms. Furthermore, trifluoropyridamole possesses dual fungicidal and nematicidal activity. Its mechanism of action involves interfering with the tricarboxylic acid cycle in the respiratory electron transport chain complex II, inhibiting mitochondrial function, preventing energy production, suppressing pathogen growth, and ultimately leading to pathogen death. It can also paralyze nematode larvae by interfering with respiration, leading to energy depletion in cells and inhibiting egg hatching.

[0004] Thiazolylphosphonate is an organophosphate nematicide with both contact and systemic action. It is effective in controlling various soil nematodes, including root-knot nematodes and cyst nematodes, and also has some efficacy in controlling underground pests. In actual agricultural production, crops often face combined infections of soil-borne diseases (such as root and stem diseases caused by Phytophthora) and nematode diseases, leading to severe yield reductions. Scientifically combining fungicides and nematicides to achieve synergistic control with a single application is of great significance for simplifying agricultural operations, reducing pesticide costs, and improving control efficacy.

[0005] In existing technologies, processing pesticide active ingredients with different chemical structures and physicochemical properties into stable composite suspensions still presents unresolved technical challenges. Due to differences in solubility, polarity, density, and other physical properties between trifluridine and thiazophosphonates, particle aggregation, growth (Oswald ripening), or stratification during storage can easily occur, affecting the physical stability and biological activity of the formulation. Furthermore, conventional suspension formulations and preparation processes struggle to simultaneously achieve optimal fineness, suspension rate, and long-term storage stability for both active ingredients, easily leading to problems such as paste formation, crusting, and enlargement of the formulation, causing inconvenience in production, transportation, and use.

[0006] Currently, there are few technologies related to suspension concentrates of trifluoropyridine amine or thiazophos. Developing a trifluoropyridine amine and thiazophos compound suspension concentrate with excellent physical and chemical stability, ease of use, and synergistic control of soil-borne diseases and nematodes is of great significance for meeting the needs of modern green agriculture. Summary of the Invention

[0007] In view of this, and in order to solve one of the above-mentioned technical problems, the present invention provides a suspension containing trifluoropyridineamine and thiazophosphine and a method for preparing the same, the specific technical solution of which is as follows: A suspension containing trifluoropyridineamine and thiazophosphonium, wherein the suspension comprises the following components by mass percentage: 1%~20% trifluoropyridineamine, 0.5%~20% thiazophosphonium, 5%~10% composite dispersant, 8%~15% suspension system, 1%~3% lecithin, 1%~6% wetting agent, 0.1%~3% thickener, 2%~7% antifreeze, 0.1%~1% defoamer, 0.1%~0.5% preservative, and deionized water to make up the balance; The preparation method of the suspension system is as follows: epoxidized soybean oil, polyethylene glycol, methyl methacrylate and fatty alcohol polyoxyethylene ether are added to a reaction vessel, heated to 45℃~65℃, and stirred at 100r / min~200r / min for 20min~30min. Then potassium dodecyl phosphate and potassium persulfate are added, the temperature is raised to 75℃~85℃, and stirring is continued for 1h~3h. After cooling, the suspension system is obtained.

[0008] Preferably, the weight ratio of the epoxidized soybean oil, polyethylene glycol, methyl methacrylate, fatty alcohol polyoxyethylene ether, potassium dodecyl phosphate, and potassium persulfate is (10~20):(2~5):(1~5):(2~5):(1~2):(0.1~0.5).

[0009] Preferably, the composite dispersant is obtained by mixing fatty alcohol polyoxyethylene ether phosphate and maleic anhydride-polystyrene copolymer in a weight ratio of (1~3):(1~2).

[0010] Preferably, the maleic anhydride-polystyrene copolymer contains 35% to 40% maleic anhydride by mass.

[0011] Preferably, the wetting agent is at least one selected from alkylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, alkyl naphthalene sulfonate, alkyl sulfate, and sodium dioctyl sulfosuccinate.

[0012] Preferably, the thickener is obtained by mixing sodium carboxymethyl cellulose and magnesium aluminum silicate in a mass ratio of (1~2):(1~5).

[0013] Preferably, the antifreeze is at least one selected from ethylene glycol, propylene glycol, urea, and glycerin.

[0014] Preferably, the defoamer is polydimethylsiloxane.

[0015] Preferably, the preservative is at least one of isothiazolinone, sodium benzoate, and Kathon.

[0016] In addition, the present invention also provides a method for preparing a suspension containing trifluoropyridineamine and thiazophosphine, the preparation method comprising the following steps: S1. Mix the composite dispersant, lecithin, wetting agent, defoamer and deionized water evenly, and stir at a speed of 100r / min~300r / min for 20min~30min to obtain dispersion A; S2. Add trifluoropyridineamine and thiazophosphonium to the dispersion A, mix evenly, and then grind until the particle size D90 of the material is ≤ 5μm to obtain dispersion B; S3. Add the suspension system to dispersion B, stir at 50 r / min to 100 r / min at 45℃ to 60℃ for 1 h to 3 h, cool to 30℃ to 35℃, add thickener, antifreeze and preservative, continue stirring for 10 min to 20 min, add deionized water to the specified mass, remove the grinding media, and obtain the suspension.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention introduces a self-synthesized specific suspension system that can form an excellent network structure and interfacial activity, making the suspension system more stable. It can also produce a synergistic effect with a specific ratio of composite dispersant (fatty alcohol polyoxyethylene ether phosphate, maleic anhydride-polystyrene copolymer) and lecithin, making the two different active ingredients more stable during storage, without hard precipitation, stratification, or paste formation, thus solving the industry problem of unstable long-term storage of compound suspensions.

[0018] 2. This invention, through the synergistic effect of specific composite dispersants and thickeners and their interaction with the suspension system, achieves a highly uniform dispersed phase, resulting in excellent suspension efficiency and dispersibility. Furthermore, it ensures efficient wetting, dispersion, and stabilization of the active ingredient, enabling rapid dispersion in water to form a highly uniform and stable diluted solution upon application. This significantly enhances the adhesion and penetration of the suspension, thereby guaranteeing uniform distribution and efficient delivery of the active ingredient to the target site, significantly improving pesticide utilization efficiency, and reducing pesticide waste and environmental pollution.

[0019] 3. This invention combines trifluoropyridineamine and thiazophosphonium to prepare a suspension. The two active ingredients with different mechanisms of action can be released and distributed more synchronously and persistently in the rhizosphere soil or crop disease infection sites after application. The disease control efficacy produced by the combination of ingredients is significantly better than that of each single agent or the simple physical mixture of the two, effectively broadening the control spectrum.

[0020] 4. The suspension preparation process of the present invention is simple, easy to industrialize, and the overall processing technology is stable and reproducible. Detailed Implementation

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0022] According to one embodiment of the present invention, a suspension containing trifluoropyridine amine and thiazophosphine comprises, by mass percentage, the following components: trifluoropyridine amine 1%~20%, thiazophosphine 0.5%~20%, composite dispersant 5%~10%, suspension system 8%~15%, lecithin 1%~3%, wetting agent 1%~6%, thickener 0.1%~3%, antifreeze 2%~7%, defoamer 0.1%~1%, preservative 0.1%~0.5%, and deionized water to make up the balance; The preparation method of the suspension system is as follows: epoxidized soybean oil, polyethylene glycol, methyl methacrylate and fatty alcohol polyoxyethylene ether are added to a reaction vessel, heated to 45℃~65℃, and stirred at 100r / min~200r / min for 20min~30min. Then potassium dodecyl phosphate and potassium persulfate are added, the temperature is raised to 75℃~85℃, and stirring is continued for 1h~3h. After cooling, the suspension system is obtained.

[0023] In one embodiment, the weight ratio of the epoxidized soybean oil, polyethylene glycol, methyl methacrylate, fatty alcohol polyoxyethylene ether, potassium dodecyl phosphate, and potassium persulfate is (10~20):(2~5):(1~5):(2~5):(1~2):(0.1~0.5).

[0024] In one embodiment, the polyethylene glycol has a molecular weight of 400 to 2000.

[0025] In one embodiment, the composite dispersant is obtained by mixing fatty alcohol polyoxyethylene ether phosphate and maleic anhydride-polystyrene copolymer in a weight ratio of (1~3):(1~2).

[0026] In one embodiment, the maleic anhydride-polystyrene copolymer contains 35% to 40% maleic anhydride by mass.

[0027] In one embodiment, the wetting agent is at least one selected from alkylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, alkyl naphthalene sulfonate, alkyl sulfate, and sodium dioctyl sulfosuccinate.

[0028] In one embodiment, the thickener is obtained by mixing sodium carboxymethyl cellulose and magnesium aluminum silicate in a mass ratio of (1~2):(1~5).

[0029] In one embodiment, the antifreeze is at least one selected from ethylene glycol, propylene glycol, urea, and glycerin.

[0030] In one embodiment, the defoamer is polydimethylsiloxane.

[0031] In one embodiment, the preservative is at least one of isothiazolinone, sodium benzoate, and Kathon.

[0032] In one embodiment, the present invention also provides a method for preparing a suspension containing trifluoropyridineamine and thiazophosphine, comprising the following steps: S1. Mix the composite dispersant, lecithin, wetting agent, defoamer and deionized water evenly, and stir at a speed of 100r / min~300r / min for 20min~30min to obtain dispersion A; S2. Add trifluoropyridineamine and thiazophosphonium to the dispersion A, mix evenly, and then grind until the particle size D90 of the material is ≤ 5μm to obtain dispersion B; S3. Add the suspension system to dispersion B, stir at 50 r / min to 100 r / min at 45℃ to 60℃ for 1 h to 3 h, cool to 30℃ to 35℃, add thickener, antifreeze and preservative, continue stirring for 10 min to 20 min, add deionized water to the specified mass, remove the grinding media, and obtain the suspension.

[0033] In one embodiment, the particle size D90 ≤ 3μm.

[0034] The above scheme combines trifluoropyridine and thiazophosphonium to prepare a suspension. The two active ingredients with different mechanisms of action can be released and distributed more synchronously and persistently in the rhizosphere soil or crop disease infection sites after application. Moreover, the suspension is more stable in storage and has better applicability.

[0035] The implementation scheme of the present invention will be described in detail below with reference to specific embodiments. The raw materials, reagents, etc. used in the embodiments that are not described in detail are all commercially available. Example 1:

[0036] A suspension containing trifluoropyridineamine and thiazophosphonium, wherein the suspension comprises the following components by mass percentage: 8.5% trifluoropyridineamine, 6.5% thiazophosphonium, 8% composite dispersant, 12% suspension system, 3% lecithin, 5% alkylphenol polyoxyethylene ether, 1% thickener, 5% ethylene glycol, 0.5% polydimethylsiloxane, 0.3% isothiazolinone, and deionized water to make up the balance; The suspension system is prepared as follows: 15 parts by weight of epoxidized soybean oil, 3 parts by weight of polyethylene glycol with a molecular weight of 400-2000, 3 parts by weight of methyl methacrylate and 4 parts by weight of fatty alcohol polyoxyethylene ether are added to a reaction vessel, heated to 65°C, stirred at 200 r / min for 25 min, then 1 part by weight of potassium dodecyl phosphate and 0.3 parts by weight of potassium persulfate are added, the temperature is raised to 80°C, and stirring is continued for 2 h. After cooling, the suspension system is obtained. The composite dispersant is obtained by mixing fatty alcohol polyoxyethylene ether phosphate and maleic anhydride-polystyrene copolymer in a weight ratio of 3:2, wherein the maleic anhydride-polystyrene copolymer contains 35% maleic anhydride by mass. The thickener is obtained by mixing sodium carboxymethyl cellulose and magnesium aluminum silicate in a mass ratio of 2:3; A method for preparing a suspension containing trifluoropyridineamine and thiazophosphine includes the following steps: S1. Mix the composite dispersant, lecithin, alkylphenol polyoxyethylene ether, polydimethylsiloxane and deionized water evenly, and stir at 250 r / min for 25 min to obtain dispersion A; S2. Add trifluoropyridineamine and thiazophosphonium to the dispersion A, mix evenly, and then grind until the particle size D90 of the material is 3μm to obtain dispersion B; S3. Add the suspension system to dispersion B, stir at 50 r / min at 60℃ for 2 h, cool to 35℃, add thickener, ethylene glycol and isothiazolinone, continue stirring for 20 min, add deionized water to the specified mass, remove the grinding media, and obtain the suspension. Example 2:

[0037] A suspension containing trifluoropyridineamine and thiazophosphonium, wherein the suspension comprises the following components by mass percentage: 8.5% trifluoropyridineamine, 6.5% thiazophosphonium, 10% composite dispersant, 10% suspension system, 3% lecithin, 6% alkylphenol polyoxyethylene ether, 0.8% thickener, 5% ethylene glycol, 0.6% polydimethylsiloxane, 0.5% isothiazolinone, and deionized water to make up the balance; The suspension system is prepared as follows: 15 parts by weight of epoxidized soybean oil, 3 parts by weight of polyethylene glycol with a molecular weight of 400-2000, 3 parts by weight of methyl methacrylate and 4 parts by weight of fatty alcohol polyoxyethylene ether are added to a reaction vessel, heated to 65°C, stirred at 200 r / min for 25 min, then 1 part by weight of potassium dodecyl phosphate and 0.3 parts by weight of potassium persulfate are added, the temperature is raised to 80°C, and stirring is continued for 2 h. After cooling, the suspension system is obtained. The composite dispersant is obtained by mixing fatty alcohol polyoxyethylene ether phosphate and maleic anhydride-polystyrene copolymer in a weight ratio of 3:2, wherein the maleic anhydride-polystyrene copolymer contains 35% maleic anhydride by mass. The thickener is obtained by mixing sodium carboxymethyl cellulose and magnesium aluminum silicate in a mass ratio of 2:3; A method for preparing a suspension containing trifluoropyridineamine and thiazophosphine includes the following steps: S1. Mix the composite dispersant, lecithin, alkylphenol polyoxyethylene ether, polydimethylsiloxane and deionized water evenly, and stir at 300 r / min for 20 min to obtain dispersion A; S2. Add trifluoropyridineamine and thiazophosphonium to the dispersion A, mix evenly, and then grind until the particle size D90 of the material is 3μm to obtain dispersion B; S3. Add the suspension system to dispersion B, stir at 50 r / min at 60℃ for 2 h, cool to 35℃, add thickener, ethylene glycol and isothiazolinone, continue stirring for 20 min, add deionized water to the specified mass, remove the grinding media, and obtain the suspension. Example 3:

[0038] A suspension containing trifluoropyridineamine and thiazophosphonium, wherein the suspension comprises the following components by mass percentage: 8.5% trifluoropyridineamine, 6.5% thiazophosphonium, 9% composite dispersant, 11% suspension system, 2% lecithin, 5% alkylphenol polyoxyethylene ether, 1% thickener, 5% ethylene glycol, 1% polydimethylsiloxane, 0.5% isothiazolinone, and deionized water to make up the balance; The suspension system is prepared as follows: 16 parts by weight of epoxidized soybean oil, 4 parts by weight of polyethylene glycol with a molecular weight of 400-2000, 4 parts by weight of methyl methacrylate and 5 parts by weight of fatty alcohol polyoxyethylene ether are added to a reaction vessel, heated to 65°C, stirred at 200 r / min for 30 min, then 1 part by weight of potassium dodecyl phosphate and 0.5 parts by weight of potassium persulfate are added, the temperature is raised to 85°C, and stirring is continued for 2 h. After cooling, the suspension system is obtained. The composite dispersant is obtained by mixing fatty alcohol polyoxyethylene ether phosphate and maleic anhydride-polystyrene copolymer in a weight ratio of 3:2, wherein the maleic anhydride-polystyrene copolymer contains 35% maleic anhydride by mass. The thickener is obtained by mixing sodium carboxymethyl cellulose and magnesium aluminum silicate in a mass ratio of 2:3; A method for preparing a suspension containing trifluoropyridineamine and thiazophosphine includes the following steps: S1. Mix the composite dispersant, lecithin, alkylphenol polyoxyethylene ether, polydimethylsiloxane and deionized water evenly, and stir at 300 r / min for 25 min to obtain dispersion A; S2. Add trifluoropyridineamine and thiazophosphonium to the dispersion A, mix evenly, and then grind until the particle size D90 of the material is 3μm to obtain dispersion B; S3. Add the suspension system to dispersion B, stir at 50 r / min at 60℃ for 2 h, cool to 35℃, add thickener, ethylene glycol and isothiazolinone, continue stirring for 20 min, add deionized water to the specified mass, remove the grinding media, and obtain the suspension.

[0039] Comparative Example 1: The difference between Comparative Example 1 and Example 3 is that sodium carboxymethyl cellulose was used to replace the composite dispersant in Comparative Example 1, while the rest was the same as in Example 3.

[0040] Comparative Example 2: The difference between Comparative Example 2 and Example 3 is that maleic anhydride-polystyrene copolymer was not added in Comparative Example 2, but otherwise it was the same as Example 3.

[0041] Comparative Example 3: The difference between Comparative Example 3 and Example 3 is that no composite dispersant was added in Comparative Example 3, but otherwise it is the same as Example 3.

[0042] Comparative Example 4: The difference between Comparative Example 4 and Example 3 is that the preparation method of the suspension system in Comparative Example 4 is different, while the rest is the same as in Example 3; The preparation method of the suspension system in Comparative Example 4 is as follows: 16 parts by weight of epoxidized soybean oil, 4 parts by weight of methyl methacrylate and 5 parts by weight of fatty alcohol polyoxyethylene ether are added to the reaction vessel, heated to 65°C, stirred at 200 r / min for 30 min, then 0.5 parts by weight of potassium persulfate are added, the temperature is raised to 85°C, and stirring is continued for 2 h. After cooling, the suspension system is obtained.

[0043] Comparative Example 5: The difference between Comparative Example 5 and Example 3 is that the preparation method of the suspension system in Comparative Example 5 is different, while the rest is the same as in Example 3; The suspension system described in Comparative Example 5 was prepared as follows: 16 parts by weight of epoxidized soybean oil and 4 parts by weight of polyethylene glycol with a molecular weight of 400-2000 were added to a reaction vessel, heated to 65°C, and stirred at 200 r / min for 30 min. Then, 1 part of potassium dodecyl phosphate was added, the temperature was raised to 85°C, and stirring was continued for 2 h. After cooling, the suspension system was obtained.

[0044] Comparative Example 6: The difference between Comparative Example 6 and Example 3 is that no suspension system was added in Comparative Example 6, but otherwise it is the same as Example 3.

[0045] The suspension samples from Examples 1-3 and Comparative Examples 1-6 were subjected to performance tests. Specifically, the water separation rate was measured after oil-water separation; low-temperature stability was performed according to section 2.2 of GB / T19137-2003 for suspension formulations; thermal decomposition rate was performed according to section 2.1 of GB / T19136-2003 for liquid formulations; and suspension rate was performed according to GB / T14825-2006. The results are shown in Table 1.

[0046] Table 1: Performance Test Results

[0047] Analysis of the data in Table 1 shows that this invention, by optimizing the composition of the suspending agent, maintains a high suspension rate even after heat storage, exhibiting no hard sedimentation, no stratification, no paste formation, and extremely low residue after pouring, demonstrating excellent stability. This solves the industry problem of unstable long-term storage of compounded suspending agents. This invention successfully combines trifluoropyridine amine and thiazophosphonates in a stable suspension system, possessing high application value and market prospects. Compared to Example 3, Comparative Example 1, which uses sodium carboxymethyl cellulose to replace the composite dispersant, showed a significant decrease in suspension rate and an increase in water separation rate, indicating that a single dispersant cannot effectively stabilize the dual-pharmaceutical system. Slight precipitation was observed in the low-temperature stability test. Comparative Example 2 lacked maleic anhydride-polystyrene copolymer, resulting in lower suspension rate and heat storage performance compared to Example 3. Slight stratification was observed in the low-temperature stability test, indicating that the addition of maleic anhydride-polystyrene copolymer in this invention plays a crucial role in enhancing steric hindrance and preventing particle aggregation. Comparative Example 3, without the addition of a composite dispersant, exhibited low suspension rate, high water separation rate, and severe decomposition, demonstrating that the dispersant is fundamental to maintaining system stability. Using fatty alcohol polyoxyethylene ether phosphate and maleic anhydride-polystyrene copolymer as composite dispersants can significantly promote suspension stability. The different preparation methods of the suspension systems in Comparative Examples 4 and 5 resulted in a significant decrease in the stabilizing effect of the suspension systems, with stratification and paste formation observed in the low-temperature stability test. This indicates that the specific suspension system of this invention can form a network structure, significantly improving the stability of the suspending agent. In Comparative Example 6, no suspension system was added, and the suspension performance and storage stability were significantly worse than those in Example 3. This indicates that the addition of a specific suspension system in this invention can make the two different active ingredients more stable during storage, without hard precipitation, stratification, or paste formation, exhibiting excellent performance.

[0048] Efficacy test: Test reagents: The suspension samples prepared in Example 3, trifluoropyridine amine suspension, and thiazophosphonate microcapsule suspension were tested for efficacy, and a blank control and an equal volume of water were set up. It should be noted that the preparation processes of trifluoropyridine amine suspension and thiazophosphonate microcapsule suspension are existing technologies and will not be described in detail here. Specifically, the suspension sample prepared in Example 3 contains 8.5% trifluoropyridine amine + 6.5% thiazophosphonate by mass percentage; the trifluoropyridine amine suspension contains 15% trifluoropyridine amine by mass percentage; and the thiazophosphonate microcapsule suspension contains 15% thiazophosphonate by mass percentage. Target pests: Cucumber root nematode disease; Tests were conducted on cucumber seedlings severely affected by root nematode disease (the nematode damage was relatively uniform across the treatment areas, and the ecological environment was the same). The treatment was carried out using a hole application method, with the same dosage applied. Random sampling was used, with 5 sampling points in each plot, and 3 seedlings randomly selected at each point, for a total of 15 cucumber seedlings. The cucumber roots were dug up, and the level of root nematode disease damage was recorded. The investigation method followed the guidelines for pesticide field efficacy trials, referring to GB / T17980.38-2000. The results are shown in Table 2.

[0049] Grade 0: No insect galls on the roots; Grade 1: There are a few small insect galls on the roots; Level 3: Two-thirds of the root system is covered with small galls; Grade 5: The roots are covered with small galls and secondary galls; Level 7: The root system forms a cluster of fibrous roots; Nematode reduction rate % = (Number of live nematodes before application - Number of live nematodes after application) / (Number of live nematodes before application) × 100; Control efficacy (%) = (CK-PT) / CK×100, where CK is the nematode reduction rate of the blank control group and PT is the nematode reduction rate after the application of the drug.

[0050] Table 2: Prevention and Control Effects

[0051] The data analysis in Table 2 shows that the efficacy of this invention increases over time. The suspension agent of this invention has a synergistic effect. The compounded formulation is significantly more effective than the single agent in controlling cucumber root-knot nematodes. The two active ingredients with different mechanisms of action can be released and distributed more synchronously and persistently in the rhizosphere soil or crop disease infection sites after application. The disease control efficacy produced by the compounded ingredients is significantly better than that of each single agent or the simple physical mixture of the two, effectively broadening the control spectrum.

[0052] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations 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 scope of the present invention.

Claims

1. A suspension containing trifluoropyridineamine and thiazophosphine, characterized in that, By mass percentage, the suspending agent comprises the following components: trifluoropyridine 1%~20%, thiazophosphine 0.5%~20%, composite dispersant 5%~10%, suspension system 8%~15%, lecithin 1%~3%, wetting agent 1%~6%, thickener 0.1%~3%, antifreeze 2%~7%, defoamer 0.1%~1%, preservative 0.1%~0.5%, and deionized water to make up the balance; The preparation method of the suspension system is as follows: epoxidized soybean oil, polyethylene glycol, methyl methacrylate and fatty alcohol polyoxyethylene ether are added to a reaction vessel, heated to 45℃~65℃, and stirred at 100r / min~200r / min for 20min~30min. Then potassium dodecyl phosphate and potassium persulfate are added, the temperature is raised to 75℃~85℃, and stirring is continued for 1h~3h. After cooling, the suspension system is obtained.

2. The suspending agent according to claim 1, characterized in that, The weight ratio of the epoxidized soybean oil, polyethylene glycol, methyl methacrylate, fatty alcohol polyoxyethylene ether, potassium dodecyl phosphate, and potassium persulfate is (10~20):(2~5):(1~5):(2~5):(1~2):(0.1~0.5).

3. The suspending agent according to claim 1, characterized in that, The composite dispersant is obtained by mixing fatty alcohol polyoxyethylene ether phosphate and maleic anhydride-polystyrene copolymer in a weight ratio of (1~3):(1~2).

4. The suspending agent according to claim 3, characterized in that, In the maleic anhydride-polystyrene copolymer, the mass percentage content of maleic anhydride is 35%~40%.

5. The suspending agent according to claim 1, characterized in that, The wetting agent is at least one of alkylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, alkyl naphthalene sulfonate, alkyl sulfate, and sodium dioctyl sulfosuccinate.

6. The suspending agent according to claim 1, characterized in that, The thickener is obtained by mixing sodium carboxymethyl cellulose and magnesium aluminum silicate in a mass ratio of (1~2):(1~5).

7. The suspending agent according to claim 1, characterized in that, The antifreeze is at least one of ethylene glycol, propylene glycol, urea, and glycerin.

8. The suspending agent according to claim 1, characterized in that, The defoamer is polydimethylsiloxane.

9. The suspending agent according to claim 1, characterized in that, The preservative is at least one of isothiazolinone, sodium benzoate, and Kathon.

10. A method for preparing a suspension containing trifluoropyridineamine and thiazophosphine, characterized in that, The preparation method is used to prepare the suspension containing trifluoropyridineamine and thiazophosphonium as described in any one of claims 1 to 9, and the preparation method includes the following steps: S1. Mix the composite dispersant, lecithin, wetting agent, defoamer and deionized water evenly, and stir at a speed of 100r / min~300r / min for 20min~30min to obtain dispersion A; S2. Add trifluoropyridineamine and thiazophosphonium to the dispersion A, mix evenly, and then grind until the particle size D90 of the material is ≤ 5μm to obtain dispersion B; S3. Add the suspension system to dispersion B, stir at 50 r / min to 100 r / min at 45℃ to 60℃ for 1 h to 3 h, cool to 30℃ to 35℃, add thickener, antifreeze and preservative, continue stirring for 10 min to 20 min, add deionized water to the specified mass, remove the grinding media, and obtain the suspension.

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