Bactericide suspending agent and preparation method thereof

Abstract

The invention belongs to the technical field of novel pesticides, and particularly provides a bactericide suspending agent and a preparation method thereof.The effective component of the bactericide suspending agent is prothioconazole, and on the basis of the effective component of the bactericide suspending agent, microencapsulated oxidized vegetable oil accounting for 5-15% of the weight of the whole bactericide is added to serve as a synergistic auxiliary agent. The prothioconazole bactericide has the advantages that the adhesion capacity of the prothioconazole bactericide on the surfaces of crops can be obviously improved, the adverse effects caused by environmental factors such as rain wash are reduced, and the absorption of the bactericide is facilitated, so that the synergistic effect is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of novel pesticides, and particularly relates to a fungicide suspension and a preparation method thereof. Background Art

[0002] Suspension concentrate (SC) is an environmentally friendly pesticide formulation that uses water as a medium. However, conventional SCs have poor adhesion and are difficult to adhere to the surfaces of gramineous crops such as wheat and corn. Because wheat and corn are covered with a hydrophobic wax layer composed of macromolecules and lipids, conventional SCs have difficulty adhering to the leaf surfaces, reducing their effectiveness.

[0003] Prothioconazole is a new triazolethione fungicide with excellent systemic activity and superior protection, treatment, and eradication properties, effectively preventing nearly all diseases. Conventional prothioconazole suspension concentrates (SCs) have difficulty wetting and adhering to leaves of wheat, corn, and other crops. To ensure the effectiveness of prothioconazole, developing a SC that enhances leaf adhesion and improves its efficacy is a pressing challenge.

[0004] Wageningen University and Leiden University in the Netherlands have jointly discovered that oxidizing vegetable oil into a thick, viscous liquid can be used to capture small pests such as thrips. When sprayed on leaves, the viscous liquid remains attached for three months. Vegetable oils contain numerous double bonds, which react readily with oxygen when exposed to air, forming peroxides. Peroxides are unstable and break down into two oxygen free radicals. These highly reactive oxygen free radicals react with the double bonds in the oil to form high molecular weight molecules, increasing their viscosity. Adding oxidized vegetable oil to a prothioconazole suspension concentrate significantly increases its adhesion to leaves.

[0005] However, during the preparation of prothioconazole suspension concentrates, the inventors discovered that after adding oxidized vegetable oil, the prothioconazole suspension concentrate tends to become a paste after grinding, or flocculates after adding water, and the paste phenomenon occurs after prolonged storage, which is not conducive to the efficacy of prothioconazole. Therefore, it is of great significance to develop a prothioconazole suspension concentrate that is stable, has strong adhesion, and is well dispersed in water. Summary of the Invention

[0006] The present invention addresses the problems in the prior art of poor adhesion of prothioconazole suspensions on wheat, the tendency of prothioconazole suspensions to become paste-like and flocculate after adding oxidized vegetable oil, and the like. Provided are a fungicide suspension and a preparation method thereof. The active ingredient of the fungicide suspension is prothioconazole. To the active ingredient, microencapsulated oxidized vegetable oil is added as a synergistic adjuvant in an amount of 5-15% by weight of the entire fungicide. The adhering ability of the prothioconazole fungicide on the surface of crops can be significantly improved, the adverse effects caused by environmental factors such as rain erosion can be reduced, the absorption of the agent can be facilitated, and thus the synergistic effect can be achieved.

[0007] The present invention first provides a fungicide suspension, which comprises an active ingredient and an adjuvant. The active ingredient is prothioconazole, and the adjuvant comprises a synergistic adjuvant, which is microencapsulated oxidized vegetable oil.

[0008] Furthermore, the active ingredient accounts for 20-50% of the total mass of the fungicide suspension, and the synergistic adjuvant accounts for 5-15% of the total mass of the fungicide suspension.

[0009] In the present invention, oxidized vegetable oil is coated to form a microencapsulated oxidized vegetable oil suspension, which is then mixed with a prothioconazole suspension to obtain a prothioconazole fungicide containing the microencapsulated oxidized vegetable oil. The stability of the prothioconazole fungicide is improved, the prothioconazole fungicide has good water dispersibility, and does not become a paste or flocculate when added with water, thereby facilitating improved control effects of the prothioconazole.

[0010] Furthermore, the vegetable oil source of the microencapsulated oxidized vegetable oil includes but is not limited to one of soybean oil, corn oil, rapeseed oil, and peanut oil; the capsule wall material of the microencapsulated oxidized vegetable oil is urea-formaldehyde resin prepolymer; and the urea-formaldehyde resin prepolymer can be prepared from urea and formaldehyde.

[0011] The preparation method of the microencapsulated oxidized vegetable oil is as follows: 1) Synthesis of urea-formaldehyde resin prepolymer: Urea, formaldehyde, and deionized water are added to a container, with a molar ratio of urea to formaldehyde being 1:1.5-2.0 and a weight ratio of formaldehyde to deionized water being 20-40%. The pH is adjusted to 7.8-8.3 with a 10% sodium hydroxide solution. The mixture is heated to 60°C-80°C and stirred at a speed of 200-400 r / min for 1-2 hours to obtain an aqueous solution of the urea-formaldehyde resin prepolymer. 2) Preparation of microencapsulated oxidized vegetable oil: adding the oxidized vegetable oil to the aqueous solution of the urea-formaldehyde resin prepolymer at room temperature, and adding an oleyl alcohol polyoxyethylene ether dispersant and an emulsifier, and stirring at a high speed of 1500 rpm-2000 rpm for 30-60 min to form a stable O / W emulsion; then reducing the speed to 200-400 rpm, adding 20% ​​hydrochloric acid to adjust the pH to 2.3-3.0, and stirring at room temperature for 2-3 hours to carry out a polycondensation reaction; after the polycondensation reaction is completed, raising the temperature to 45°C to solidify the capsule wall, and maintaining the temperature at 40-50°C until the reaction reaches the end point (the end point is determined by observing more than 90% capsule formation under a microscope), then adjusting the pH to 6.5-7.5 with a 10% sodium hydroxide solution, adding an appropriate amount of water, and adjusting the mass proportion of the microencapsulated oxidized vegetable oil to 30%-50%, to prepare a microencapsulated oxidized vegetable oil emulsion.

[0012] The preparation method of the oxidized vegetable oil comprises: weighing the vegetable oil into a reaction vessel, heating it to 80-90°C and stirring it at a stirring rate of 1000-1500 r / min, and carrying out an oxidation reaction in an air atmosphere using air as an oxidant until the viscosity of the liquid reaches 900-1000 Pa·s, thereby obtaining the oxidized vegetable oil.

[0013] The obtained microencapsulated oxidized vegetable oil is preferably prepared and used immediately, that is, after the capsule wall is solidified at 40-50°C, the pH is adjusted and an appropriate amount of water is added to adjust the mass ratio of the microencapsulated oxidized vegetable oil to 30-50%, and then it is used directly.

[0014] As a preferred embodiment, the emulsifier is selected from but not limited to one or more of dodecylbenzene sulfonate emulsifiers, phosphate emulsifiers, glycoside emulsifiers, polyoxyethylene ether emulsifiers or carbamate emulsifiers; the mass ratio of the oxidized vegetable oil to the aqueous solution of urea-formaldehyde resin prepolymer is 4:3-2:1; the mass ratio of the oleyl alcohol polyoxyethylene ether dispersant to the oxidized vegetable oil is 1-6:30; and the mass ratio of the emulsifier to the oxidized vegetable oil is 1-10:30.

[0015] Furthermore, the balance of the fungicide suspension after removing the active ingredients and adjuvants is supplemented with water, and the adjuvants include at least the above-mentioned synergistic adjuvants and also include one or more of dispersants, emulsifiers, wetting agents, antifreeze agents, thickeners, and defoaming agents.

[0016] Furthermore, the dispersant is one or more of a carboxylate dispersant, a block polyether dispersant, and an oleyl alcohol polyoxyethylene ether dispersant; In some embodiments of the present invention, the carboxylate dispersant is SP-27001 from Jiangsu Qingyu Chemical Technology Co., Ltd. or GY-D07 from Beijing Guangyuan Yinong Chemical Co., Ltd.; and the block polyether dispersant is Ethylan NS-500LQ from Akzo Nobel.

[0017] Furthermore, the wetting agent is one or more of dioctyl sulfosuccinate and opening powder BX.

[0018] Furthermore, the emulsifier is one or more of non-ionic composite emulsifier FTRTVE101, emulsifier HY-536H, and tristyrylphenol polyoxyethylene polyoxypropylene ether, and the non-ionic composite emulsifier FTRTVE101 is purchased from Guangzhou Fangzhong Chemical Co., Ltd.

[0019] Furthermore, the antifreeze agent is one or both of ethylene glycol and glycerol.

[0020] Furthermore, the thickener is one or more of xanthan gum, magnesium aluminum silicate, and white carbon black.

[0021] Furthermore, the defoaming agent is a polysiloxane defoaming agent SAG1572, and the polysiloxane defoaming agent SAG1572 is purchased from Maitu Advanced Materials Group.

[0022] The present invention also provides a method for preparing the fungicide suspension, comprising the following steps: (1) First, add water, dispersant, wetting agent, emulsifier, defoamer, and antifreeze into the reactor according to the proportions and stir to mix them evenly; (2) adding prothioconazole technical and thickener according to the proportion, stirring at a speed of 500-800 r / min and shearing at 10000 rpm-16000 rpm for 5-10 min to mix uniformly to obtain a mixed solution; (3) The mixed solution obtained in step (2) is added to a sand mill and ground to a particle size D90 ≤ 5 μm. The temperature is controlled below 25° C. during the grinding process. After the grinding is completed, microencapsulated oxidized vegetable oil is added and stirred evenly to obtain a prothioconazole suspension.

[0023] In the above preparation method, the microencapsulated oxidized vegetable oil is added at the end and does not participate in the grinding process, which can further protect the stability of the microencapsulated oxidized vegetable oil.

[0024] Prothioconazole has a good control effect on most diseases. However, the surface of gramineous crops such as wheat and corn is covered with a hydrophobic wax layer composed of macromolecules and lipids. As a result, when conventional suspension concentrates are used, the agent is difficult to adhere to the wheat surface, thereby reducing the control effect of the agent. The present invention adds a synergistic auxiliary agent, microencapsulated oxidized vegetable oil, to the prothioconazole suspension concentrate. The preparation is stable and has good water dispersibility. It does not become creamy or flocculate when added with water during storage and use. The adhesion of prothioconazole to the leaf surface can be increased, which is conducive to prolonging the effective time for the drug to exert its control effect and increasing the control effect of the drug. The synergistic auxiliary agent is derived from vegetable oil, has strong affinity with the environment, is easily obtained, and is conducive to environmental protection.

[0025] Compared with the existing technology, the main technical effects of this application are as follows: (1) The present invention adds oxidized vegetable oil to the prothioconazole suspension concentrate, which can significantly increase the adhesion of the prothioconazole suspension concentrate to wheat leaves, which is beneficial to prolonging the effective time for the drug to exert its preventive and control effects and increasing the preventive and control effects of the prothioconazole suspension concentrate.

[0026] (2) The oxidized vegetable oil of the synergistic adjuvant comes from soybean oil, corn oil, rapeseed oil and peanut oil. It is sourced from vegetable oil, has strong affinity with the environment, is easy to obtain, and is beneficial to environmental protection.

[0027] (3) Compared with vegetable oil, oxidized vegetable oil has a large molecular weight and high viscosity; however, if oxidized vegetable oil is added directly to the suspension without treatment, it will cause creaming and flocculation. In the present invention, the oxidized vegetable oil is microencapsulated, which has better compatibility with the prothioconazole suspension and will not cause adverse phenomena such as creaming and flocculation.

[0028] (4) The formulation of prothioconazole is a water suspension concentrate, which uses water as the dispersion medium and is green, environmentally friendly and pollution-free. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The results of the microscopic examination of the suspension concentrates of Example 1 and Comparative Example 5 after adding water in Experimental Example 1 are shown in FIG. Figure 1 A is Example 1, Figure 1 B is comparative example 5. DETAILED DESCRIPTION

[0030] The technical solution of the present invention will be further described below in conjunction with specific embodiments. These embodiments are only used to illustrate the technical solution of the present invention in more detail and should not be construed as limiting the scope of protection of the present invention.

[0031] The percentages below are by weight unless otherwise specified, and the additives used are conventional additives in the art.

[0032] Unless otherwise specified, the following experimental methods are conventional methods in the art.

[0033] SP-27001 used in the following examples and comparative examples was purchased from Jiangsu Qingyu Chemical Technology Co., Ltd.; GY-D07 was purchased from Beijing Guangyuan Yinong Chemical Co., Ltd.; Ethylan NS-500LQ was purchased from Akzo Nobel; FTRTVE101 was purchased from Guangzhou Fangzhong Chemical Co., Ltd.; and emulsifier HY-536H was purchased from Cangzhou Hongyuan Agrochemical Co., Ltd. The remaining substances, reagents (such as dioctyl sulfosuccinate, flaking powder BX, etc.) and other raw materials are all readily available on the market.

[0034] The defoaming agents used in the following examples and comparative examples are all polysiloxane defoaming agent SAG1572, purchased from Maitu Advanced Materials Group; soybean oil is used as the vegetable oil.

[0035] The following microencapsulated oxidized vegetable oil was prepared by the following method: 1) Preparation of Oxidized Vegetable Oil: Weighed soybean oil was added to a single-necked flask and oxidized in an air atmosphere at 90°C in an electric heating mantle at 600 rpm. The desired oxidized vegetable oil was obtained when the viscosity of the slurry reached 950 Pa·s (measured at 25°C, rotor #3, 30 rpm, using an NDJ-5AT digital viscometer). 2) Synthesis of Urea-Formaldehyde Resin Prepolymer: Urea and formaldehyde were added to a three-necked flask equipped with a thermometer and a stirrer at a molar ratio of 1:1.5, with the weight ratio of formaldehyde to deionized water being 30%. The pH was adjusted to 8.0 with a 10% sodium hydroxide solution. The temperature was raised to 70°C and stirred at 300 rpm for 2 h to obtain an aqueous solution of the urea-formaldehyde resin prepolymer. 3) Preparation of Microencapsulated Oxidized Vegetable Oil: At room temperature, 40g of oxidized vegetable oil was added to 30g of urea-formaldehyde resin prepolymer aqueous solution, along with 1.5g of oleyl alcohol polyoxyethylene ether dispersant and 2g of emulsifier HY-536H. The mixture was stirred at 2000 rpm for 50 minutes to form a stable O / W emulsion. The speed was then reduced to 300 rpm, and 20% hydrochloric acid was added to adjust the pH to approximately 2.5. The mixture was stirred at room temperature for 2 hours to allow for polycondensation. After the polycondensation reaction, the temperature was raised to 45°C to solidify the capsule wall. After reaching the reaction endpoint (microscopic observation of more than 90% capsule formation indicated), the pH was adjusted to approximately 7.5 with 10% sodium hydroxide solution. An appropriate amount of water was added to adjust the oxidized vegetable oil content to 50%. The microencapsulated oxidized vegetable oil was prepared and used immediately. The amount of microencapsulated oxidized vegetable oil added in the following examples and comparative examples is calculated based on the pure substance, not the emulsion.

[0036] The prothioconazole suspension concentrates in the following Examples 1-4 and Comparative Examples 1-4 were prepared by the following steps: (1) First, add water, dispersant, wetting agent, emulsifier, defoamer, and antifreeze into the reactor according to the proportions and stir to mix them evenly; (2) adding prothioconazole technical and thickener according to the proportion, stirring at a speed of 500 r / min and shearing at 15000 rpm for 10 min to mix uniformly to obtain a mixed solution; (3) The mixed solution obtained in step (2) is added to a sand mill and ground to a particle size D90 ≤ 5 μm. The temperature is controlled below 25° C. during the grinding process. After the grinding is completed, microencapsulated oxidized vegetable oil is added and stirred evenly to obtain a prothioconazole suspension.

[0037] Example 1 20% prothioconazole suspension concentrate, calculated by weight percentage, comprises the following components: Prothioconazole, 20%; microencapsulated oxidized vegetable oil, 15%; SP-27001, 3%; dioctyl sulfosuccinate, 2%; FTRTVE101, 10%; ethylene glycol, 5%; white carbon black, 0.5%; xanthan gum, 0.2%; defoamer, 0.2%; water to 100%.

[0038] Example 2 25% prothioconazole suspension concentrate, calculated by weight percentage, comprises the following components: Prothioconazole, 25%; microencapsulated oxidized vegetable oil, 10%; SP-27001, 3%; diethylhexyl sulfosuccinate, 2%; FTRTVE101, 8%; tristyrylphenol polyoxyethylene polyoxypropylene ether, 2%; ethylene glycol, 4%; magnesium aluminum silicate, 0.8%; xanthan gum, 0.15%; defoamer, 0.2%; water to 100%.

[0039] Example 3 30% prothioconazole suspension concentrate, calculated by weight percentage, comprises the following components: Prothioconazole, 30%; microencapsulated oxidized vegetable oil, 10%; GY-07, 3%; GY-DB1700, 1%; Lakai powder BX, 2%; FTRTVE101, 5%; tristyrylphenol polyoxyethylene polyoxypropylene ether, 5%; ethylene glycol, 3%; magnesium aluminum silicate, 0.5%; xanthan gum, 0.1%; defoamer, 0.2%; water to make up 100%.

[0040] Example 4 40% prothioconazole suspension concentrate, calculated by weight percentage, comprises the following components: Prothioconazole, 40%; microencapsulated oxidized vegetable oil, 8%; GY-07, 3%; GY-DB1700, 1%; Lakai powder BX, 2%; FTRTVE101, 3%; tristyrylphenol polyoxyethylene polyoxypropylene ether, 7%; glycerol, 3%; white carbon black, 0.5%; xanthan gum, 0.05%; defoamer, 0.2%; water to make up 100%.

[0041] Comparative Example 1 20% prothioconazole suspension concentrate, calculated by weight percentage, comprises the following components: Prothioconazole, 20%; SP-27001, 3%; dioctyl sulfosuccinate, 2%; FTRTVE101, 10%; ethylene glycol, 5%; white carbon black, 0.5%; xanthan gum, 0.2%; defoamer, 0.2%; water to make up 100%.

[0042] Compared with Example 1, Comparative Example 1 did not add the synergistic adjuvant microencapsulated oxidized vegetable oil, and the remaining components and preparation method were the same as those of Example 1.

[0043] Comparative Example 2 25% prothioconazole suspension concentrate, calculated by weight percentage, comprises the following components: Prothioconazole, 25%; SP-27001, 3%; dioctyl sulfosuccinate, 2%; FTRTVE101, 8%; tristyrylphenol polyoxyethylene polyoxypropylene ether, 2%; ethylene glycol, 4%; magnesium aluminum silicate, 0.8%; xanthan gum, 0.15%; defoamer, 0.2%; water to make up 100%.

[0044] Compared with Example 2, Comparative Example 2 did not add the synergistic adjuvant microencapsulated oxidized vegetable oil, and the remaining components and preparation method were the same as those of Example 2.

[0045] Comparative Example 3 30% prothioconazole suspension concentrate, calculated by weight percentage, comprises the following components: Prothioconazole, 30%; GY-07, 3%; GY-DB1700, 1%; Lakai powder BX, 2%; FTRTVE101, 5%; Tristyrylphenol polyoxyethylene polyoxypropylene ether, 5%; Ethylene glycol, 3%; Magnesium aluminum silicate, 0.5%; Xanthan gum, 0.1%; Defoamer, 0.2%; Water to make up 100%.

[0046] Compared with Example 3, Comparative Example 3 did not add the synergistic adjuvant microencapsulated oxidized vegetable oil, and the remaining components and preparation method were the same as those of Example 3.

[0047] Comparative Example 4 40% prothioconazole suspension concentrate, calculated by weight percentage, comprises the following components: Prothioconazole, 40%; GY-07, 3%; GY-DB1700, 1%; Lakai powder BX, 2%; FTRTVE101, 3%; Tristyrylphenol polyoxyethylene polyoxypropylene ether, 7%; Glycerol, 3%; White carbon black, 0.5%; Xanthan gum, 0.05%; Defoamer, 0.2%; Water to make up 100%.

[0048] Compared with Example 4, Comparative Example 4 did not add the synergistic adjuvant microencapsulated oxidized vegetable oil, and the remaining components and preparation method were the same as those of Example 4.

[0049] Comparative Example 5 20% prothioconazole suspension concentrate, calculated by weight percentage, comprises the following components: Prothioconazole, 20%; oxidized vegetable oil, 15%; SP-27001, 3%; dioctyl sulfosuccinate, 2%; FTRTVE101, 10%; ethylene glycol, 5%; white carbon black, 0.5%; xanthan gum, 0.2%; defoamer, 0.2%; water to make up 100%.

[0050] Compared with Example 1, in Comparative Example 5, no microencapsulated oxidized vegetable oil was added, but oxidized vegetable oil of equal mass ratio was used instead.

[0051] The preparation method of the prothioconazole suspension concentrate of Comparative Example 5 is the same as that of Example 1, except that oxidized vegetable oil is used instead of the microencapsulated oxidized vegetable oil in Example 1, and the other steps and conditions are consistent with those in Example 1.

[0052] Comparative Example 6 30% prothioconazole suspension concentrate, calculated by weight percentage, comprises the following components: Prothioconazole, 30%; microencapsulated oxidized vegetable oil, 10%; GY-07, 3%; GY-DB1700, 1%; Lakai powder BX, 2%; FTRTVE101, 5%; tristyrylphenol polyoxyethylene polyoxypropylene ether, 5%; ethylene glycol, 3%; magnesium aluminum silicate, 0.5%; xanthan gum, 0.1%; defoamer, 0.2%; water to make up 100%.

[0053] The prothioconazole suspension concentrate of Comparative Example 6 was prepared by the following steps: (1) First, water, dispersant, wetting agent, emulsifier, defoamer, antifreeze and microencapsulated oxidized vegetable oil are added to a reaction kettle according to the proportions and stirred to mix them evenly; (2) adding prothioconazole technical, thickener, and oxidized vegetable oil according to the proportion, stirring and shearing at a speed of 500 r / min and shearing at 15000 rpm for 10 min to mix them uniformly to obtain a mixed solution; (3) The mixed solution obtained in step (2) is added to a sand mill and ground to a particle size D90 ≤ 5 μm. The temperature is controlled below 25° C. during the grinding process. After the grinding is completed, the mixture is stirred evenly to obtain a prothioconazole suspension.

[0054] Compared with Example 3, in Comparative Example 6, the microencapsulated oxidized vegetable oil was stirred and mixed together with auxiliary agents such as a dispersant in step (1).

[0055] Comparative Example 7 20% prothioconazole suspension concentrate, calculated by weight percentage, comprises the following components: Prothioconazole, 20%; microencapsulated vegetable oil, 15%; SP-27001, 3%; dioctyl sulfosuccinate, 2%; FTRTVE101, 10%; ethylene glycol, 5%; white carbon black, 0.5%; xanthan gum, 0.2%; defoamer, 0.2%; water to make up 100%.

[0056] Compared to Example 1, Comparative Example 7 did not add microencapsulated oxidized vegetable oil, but instead used an equal weight ratio of microencapsulated vegetable oil. The microencapsulated vegetable oil used in this Comparative Example was prepared using the same method as the aforementioned microencapsulated oxidized vegetable oil, with the only difference being that the vegetable oil in this embodiment was not oxidized, but was replaced with unoxidized vegetable oil.

[0057] The preparation method of the prothioconazole suspension concentrate of Comparative Example 7 is the same as that of Example 1, except that microencapsulated vegetable oil is used instead of the microencapsulated oxidized vegetable oil in Example 1, and the other steps and conditions are consistent with Example 1.

[0058] Experimental Example 1 Storage stability and water stability test: Carry out sample testing as follows: 1. Pesticide thermal storage stability: The samples were subjected to thermal storage stability test and stored at (54±2)℃ for 14 days. The samples were tested after storage. The main tests were active ingredient content and suspension rate. The suspension rate was determined according to the suspension rate determination method of GB / T14825 for pesticides. The active ingredient content was determined by high performance liquid chromatography. 2. After the preparation of the prothioconazole suspension concentrate, observe the state of the sample and dilute the prothioconazole suspension concentrate sample with water (take 1g of the suspension concentrate sample and add it to 100g of water and stir to disperse it). Place it under a microscope to observe whether there is flocculation. After grinding, observe whether the sample flows normally. If it does not flow, it is a paste.

[0059] The above experiment was carried out on Examples 1-4 and Comparative Examples 1-8. The specific data are shown in Table 1: Table 1 Thermal storage stability and microscopic test results of prothioconazole suspension The microscopic test results of the prothioconazole suspension concentrates of Example 1 and Comparative Example 5 after being diluted with water are as follows: Figure 1 As shown, Figure 1 A is Example 1, Figure 1B is Comparative Example 5. The results show that if the oxidized vegetable oil is not microencapsulated, flocculation and thermal paste formation will occur when the oxidized vegetable oil is directly added to the sample of the prothioconazole suspension concentrate, resulting in a low suspension rate and poor stability. Adding microencapsulated oxidized vegetable oil can prepare a relatively stable prothioconazole suspension concentrate, thereby improving the problem that oxidized vegetable oil is difficult to apply to prothioconazole suspension concentrates. In contrast to Example 3 and Comparative Example 6, the order of adding the microencapsulated oxidized vegetable oil is different. In Example 3, the microencapsulated oxidized vegetable oil is added last and does not participate in the grinding process, which can further protect the stability of the microencapsulated oxidized vegetable oil.

[0060] Experimental Example 2 Adhesion Performance Test of Prothioconazole Suspension Concentrate The leaf adhesion of prothioconazole suspension concentrate is measured by its leaf retention. Leaf retention testing can be performed using the method described in "2.2.9 Determination of Leaf Retention of Nanosuspension Concentrates" in the reference (Zhiheng, Construction of Leaf-Adhesive Pesticide Delivery System and Investigation of Adhesion Mechanisms [D]. Beijing: Chinese Academy of Agricultural Sciences, 2020). For example, the following method can be used: The leaf surface retention of prothioconazole on the surface of wheat leaves was determined using the leaf immersion weighing method. Each experiment was repeated 5 times, and the arithmetic mean of the results was taken. The retention of deionized water on the wheat crop leaves was used as a blank control. Specifically, the wheat samples were removed from the climate incubator and the leaves were first rinsed with deionized water to reduce experimental errors. After the leaves were naturally dried, a 1.5 cm diameter punch was used to punch out wheat leaf discs of the same size. The area S (cm) of the discs was measured using a leaf area meter. 2 ). Use a thousandth precision electronic balance to weigh, dilute the fungicide with water, and dilute it according to the concentration of the active ingredient (prothioconazole original drug) with water shown in Table 2 to obtain prothioconazole pesticide solution; put a pair of tweezers in the experimental pesticide solution, peel and clear it, and thoroughly immerse the circular discs of the same size as the wheat leaves obtained by the puncher in the pesticide solution for 20 seconds, record the time with a stopwatch, record the weight W1 (mg), take out the leaves, and wait until the pesticide droplets on the leaves stop dripping, transfer the wheat leaves soaked in the solution (make sure no droplets drip during the transfer process), put the tweezers back into the test solution, and record the weight W2 (mg) of the leaves. The retention amount Rr (mg / cm 2 ) is calculated as follows: Rr=(W1-W2) / S.

[0061] The test results of the retention of prothioconazole suspension concentrate on wheat leaves are shown in Table 2: Table 2 Wheat leaf retention test results of Examples 1-4 and Comparative Examples 1-8 The retention rate reflects the degree of adhesion of the prothioconazole suspension on wheat leaves; stronger adhesion results in higher retention rates. Comparison of the above examples with the comparative examples reveals that the addition of microencapsulated oxidized vegetable oil to the prothioconazole suspension increases the retention rate of the solution on wheat leaves. This phenomenon occurs because the microencapsulated oxidized vegetable oil, derived from plants, has a greater affinity for wheat leaves. This, combined with the strong adhesion of the oxidized vegetable oil, increases the retention rate of prothioconazole on wheat leaves.

[0062] Experimental Example 3 Field efficacy test Test agents: Examples 1-4 and Comparative Examples 1-7 and water control; Experimental Methods: The experiment was conducted at a wheat planting cooperative in Dianzi Town, Boxing County, Shandong Province. The soil was sandy loam, and the previous crop was corn. The wheat variety tested was Yangmai 15 (a variety susceptible to scab). A total of 13 treatments (including Examples 1-4, Comparative Examples 1-7, and a water control) were included. Each treatment had four replicates, each replicate corresponding to a plot of 50 m2. 2 For each treatment, the solution was prepared at 10g of active ingredient per 30kg of water. After application, wheat was surveyed at the milky stage. Samples were taken at five diagonal points in each plot, with 100 wheat plants surveyed consecutively at each point, for a total of 500 plants. The number of diseased ears at all levels of scab was accurately recorded to calculate the scab disease rate, disease index, and control efficacy.

[0063] The severity grading standard of wheat scab is based on the disease situation of wheat ears. The grading method is: Level 0: The whole ear is disease-free; Level 1: The area of ​​diseased spikelets accounts for less than 1 / 4 of the entire spike area; Level 3: The area of ​​diseased spikelets accounts for 1 / 4-1 / 2 of the entire spike area; Level 5: The area of ​​diseased spikelets accounts for 1 / 2-3 / 4 of the whole spike area; Level 7: The area of ​​diseased spikelets accounts for more than 3 / 4 of the total spike area.

[0064] The diseased ear rate, disease index and control effect are calculated according to the following formula: Direct impact on crops: Observe whether the pesticide has any damage to the crops. If so, record the type and extent of damage. Record damage as follows: Using the pesticide damage grading method, record the damage level for each plot, expressing it as -, +, ++, ++++, or ++++++.

[0065] Phytotoxicity grading method: -: No pesticide damage; +: Mild pesticide damage, no impact on normal crop growth; ++: obvious damage from pesticide, but can be recovered and will not cause crop yield reduction; ++++: High level of pesticide damage, affecting the normal growth of crops and causing a certain degree of loss in crop yield and quality; ++++++: Severe pesticide damage, stunted crop growth, and loss of crop yield and quality.

[0066] The test results are shown in Table 3: Table 3 Field test results From the table above we can see that: 1. From the time of application of each treatment to the harvest period, wheat production was normal, with no signs of pesticide damage, indicating that each treatment was safe for wheat growth and development. 2. Compared with Comparative Examples 1-4, the addition of the microencapsulated oxidized vegetable oil system showed that the control effect of Examples on wheat scab was higher than that of Comparative Examples; 3. Compared with Example 1 and Comparative Example 5, the disease index of Comparative Example 5 was significantly higher than that of Example 1, and the control effect was significantly lower than that of Example 1. This indicates that even if oxidized vegetable oil is added, flocculation of the sample with water will affect the control effect of the prothioconazole suspension concentrate. 4. Compared with Comparative Example 7, Example 1 has a higher control effect than Comparative Example 7, indicating that oxidized vegetable oil can increase the retention of the liquid medicine on the leaves and improve the control effect.

[0067] In summary, the preparation of the fungicide suspension provided by the present invention can significantly increase the adhesion and retention of the prothioconazole suspension on wheat leaves by adding microencapsulated oxidized vegetable oil, which is beneficial for extending the effective time for the drug to exert its preventive and therapeutic effects, thereby increasing the preventive and therapeutic effects of the prothioconazole suspension. The present invention can reduce the dosage of chemical pesticides and delay the resistance of wheat scab. The oxidized vegetable oil can increase the retention of the drug solution on crop leaves, and the microencapsulated vegetable oil can ensure the stability of the product when preparing the prothioconazole suspension, inhibiting the paste phenomenon of products containing oxidized vegetable oil during preparation and the flocculation phenomenon that occurs when diluting with water, thereby better exerting the efficacy of the drug.

[0068] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any equivalent replacement, modification, etc. made by technicians in this field without any creative work within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A fungicide suspension, comprising an active ingredient and an adjuvant, wherein the active ingredient is prothioconazole and the adjuvant contains a synergistic adjuvant, characterized in that: The synergistic adjuvant is microencapsulated oxidized vegetable oil, the active ingredient accounts for 20-50% of the total mass of the fungicide suspension, and the synergistic adjuvant accounts for 5-15% of the total mass of the fungicide suspension.

2. The fungicide suspension according to claim 1, wherein The vegetable oil source of the microencapsulated oxidized vegetable oil is one of soybean oil, corn oil, rapeseed oil and peanut oil; the capsule wall material of the microencapsulated oxidized vegetable oil is urea-formaldehyde resin prepolymer; the urea-formaldehyde resin prepolymer is prepared by urea and formaldehyde.

3. The fungicide suspension according to claim 1 or 2, characterized in that The preparation method of the microencapsulated oxidized vegetable oil is as follows: 1) Synthesis of urea-formaldehyde resin prepolymer: Urea, formaldehyde, and deionized water are added to a container, with a molar ratio of urea to formaldehyde being 1:1.5-2.0 and a weight ratio of formaldehyde to deionized water being 20-40%. The pH is adjusted to 7.8-8.3 with a 10% sodium hydroxide solution. The mixture is heated to 60°C-80°C and stirred at a speed of 200-400 r / min for 1-2 hours to obtain an aqueous solution of the urea-formaldehyde resin prepolymer. 2) Preparation of microencapsulated oxidized vegetable oil: adding the oxidized vegetable oil to the aqueous solution of the urea-formaldehyde resin prepolymer at room temperature, and adding an oleyl alcohol polyoxyethylene ether dispersant and an emulsifier, and stirring at a high speed of 1500-2000 r / min for 30-60 minutes to form a stable O / W emulsion; then reducing the speed to 200-400 r / min, adding 20% ​​hydrochloric acid to adjust the pH to 2.3-3.0, and stirring at room temperature for 2-3 hours to carry out a polycondensation reaction; after the polycondensation reaction is completed, raising the temperature to 45°C to solidify the capsule wall, maintaining the temperature at 40-50°C until the reaction reaches the end point, adjusting the pH to 6.5-7.5 with a 10% sodium hydroxide solution, and adding water to adjust the mass proportion of the microencapsulated oxidized vegetable oil to 30%-50%, thereby preparing a microencapsulated oxidized vegetable oil emulsion.

4. The fungicide suspension according to claim 3, wherein The preparation method of the oxidized vegetable oil comprises: weighing the vegetable oil into a reaction vessel, heating it to 80-90°C and stirring it at a stirring rate of 1000-1500 r / min, and carrying out an oxidation reaction in an air atmosphere using air as an oxidant until the viscosity of the liquid reaches 900-1000 Pa·s, thereby obtaining the oxidized vegetable oil.

5. The fungicide suspension according to claim 3, wherein: The emulsifier is selected from at least one of dodecylbenzene sulfonate emulsifiers, phosphate emulsifiers, glycoside emulsifiers, polyoxyethylene ether emulsifiers or carbamate emulsifiers; the mass ratio of the oxidized vegetable oil to the aqueous solution of urea-formaldehyde resin prepolymer is 4:3-2:1; the mass ratio of the oleyl alcohol polyoxyethylene ether dispersant to the oxidized vegetable oil is 1-6:30; and the mass ratio of the emulsifier to the oxidized vegetable oil is 1-10:

30.

6. The fungicide suspension according to claim 1, characterized in that The auxiliary agent also includes one or more of a dispersant, an emulsifier, a wetting agent, an antifreeze agent, a thickener, and a defoaming agent.

7. The fungicide suspension according to claim 6, characterized in that The dispersant is one or more of a carboxylate dispersant, a block polyether dispersant, and an oleyl alcohol polyoxyethylene ether dispersant; the wetting agent is one or more of dioctyl succinate sulfonate and pull-opening powder BX; and the emulsifier is one or more of a nonionic composite emulsifier FTRTVE101, an emulsifier HY-536H, and tristyrylphenol polyoxyethylene polyoxypropylene ether.

8. The fungicide suspension according to claim 6, characterized in that The antifreeze agent is one or two of ethylene glycol and glycerol; the thickener is one or more of xanthan gum, magnesium aluminum silicate, and white carbon black; the defoaming agent is a polysiloxane defoaming agent SAG1572, and the polysiloxane defoaming agent SAG1572 is purchased from Maitu Advanced Materials Group.

9. The method for preparing the bactericide suspension according to claim 1, wherein The following steps are involved: (1) First, add water, dispersant, wetting agent, emulsifier, defoamer, and antifreeze into the reactor according to the proportions and stir to mix them evenly; (2) adding prothioconazole technical and thickener according to the proportion, stirring at a speed of 500-800 r / min and shearing at 10000 rpm-16000 rpm for 5-10 min to mix uniformly to obtain a mixed solution; (3) The mixed solution obtained in step (2) is added to a sand mill and ground to a particle size D90 ≤ 5 μm. The temperature is controlled below 25° C. during the grinding process. After the grinding is completed, microencapsulated oxidized vegetable oil is added and stirred evenly to obtain a prothioconazole suspension.

Images