Preparation method of micro-capsule suspending agent containing oxyfluorfen

Abstract

The invention relates to the technical field of pesticide preparation, and provides a preparation method of an oxyfluorfen-containing microcapsule suspending agent, which comprises the following steps: S1, mixing oxyfluorfen, a dispersant, an organic solvent and water, fully stirring and dispersing to obtain a mixture, and shearing the mixture by a high-speed shearing method to obtain a stable oxyfluorfen suspension; s2, mixing the oxyfluorfen suspension in the S1, an emulsifier and water to obtain a solution A; s3, mixing the oil-phase wall material, the microencapsulated medicament and the organic solvent to obtain a solution B, and mixing the water-phase wall material and water to obtain a solution C; s4, dropwise adding the solution B in the S3 into the solution A, and shearing while stirring in the dropwise adding process until the solution B and the solution A are completely mixed to obtain a mixed solution; and S5, continuously dropwise adding the solution C into the mixed solution in the step S4, and stirring in the dropwise adding process to obtain the stable oxyfluorfen microcapsule suspending agent.

Description

Technical Field

[0001] The present invention relates to the technical field of pesticide preparation, and specifically, to a preparation method of a microcapsule suspension containing oxyfluorfen. Background Art

[0002] Oxyfluorfen is an organic compound with the chemical formula C15H11ClF3NO4. It usually appears as a white to orange or red-brown crystalline solid with a smoky odor. Oxyfluorfen is a selective, pre-emergence and post-emergence contact herbicide with extremely low dosage. It is mainly used in rice, soybeans, wheat, cotton, corn, oil palm, vegetables, orchards, etc. to control broad-leaved weeds and some gramineous weeds, such as Commelina communis, Echinochloa crusgalli, Cyperus rotundus, Sesbania cannabina, Bromus japonicus, Datura stramonium, etc. Oxyfluorfen kills weeds mainly after the drug is absorbed through the coleoptile and mesocotyl. At present, if a large amount of oxyfluorfen is continuously used alone as a herbicide, weeds are likely to develop drug resistance within 3 to 5 years. To address this situation, the microcapsule suspension technology can encapsulate pesticides and suspend them in water. It is a new type of pesticide formulation with a long effective period, less organic solvent content, and less harm to operators. To improve the drug use effect;

[0003] For example, the "suspension-microcapsule suspension of oxyfluorfen and S-metolachlor and its preparation method" disclosed in Chinese Patent (Publication No.: CN112471143A) has the following steps in the preparation method:

[0004] (1) Preparation of S-metolachlor microcapsule suspension by in-situ method / interface method

[0005] Using the in-situ polymerization method, under high-speed stirring, a 25% urea-formaldehyde resin prepolymer prepared from formaldehyde and urea, as well as an emulsifier, a dispersant, a protective agent, and an antifoaming agent, etc. are added to the S-metolachlor mixture. When a stable O / W emulsion is formed, an acid solution is added to catalyze the reaction. After the wall of the capsule is cured by heating, a thickener, an antifreeze, a stabilizer, and the remaining water are added to form the S-metolachlor microcapsule suspension. Using the interface polymerization method, an emulsifier and a polymer oil-phase monomer (capsule body) are added to the S-metolachlor mixture as the oil phase. Under high-speed stirring, the oil phase is slowly added to the aqueous phase containing the dispersant and the protective agent. When a stable O / W emulsion is formed, an ethylenediamine solution is added to catalyze the reaction. After the wall of the capsule is cured by heating, a thickener, an antifreeze, a stabilizer, and the remaining water are added to form the S-metolachlor microcapsule suspension.

[0006] (2) Preparation of oxyfluorfen suspension by grinding method / high-speed shearing method

[0007] By grinding method, oxyfluorfen technical, dispersant, wetting agent, thixotropic agent, defoamer and process water are added into the preparation kettle, dispersed by high-speed shearing, and multi-stage grinding by colloid mill and sand mill makes the particle size 98% less than 10.0 μm, and finally thickener, antifreeze agent and remaining water are added and stirred to form oxyfluorfen suspension concentrate.

[0008] (3) Mixing

[0009] (4) Mix the qualified S-isopropylamine microcapsule suspension and oxyfluorfen suspension in proportion, and appropriately add thickeners and stabilizers to ensure that the product performance is stable and qualified. Take samples for testing, and transport them to the finished product storage tank after they pass the test, and then package them into products.

[0010] However, in the process of preparing microcapsule suspension of oxyfluorfen, this type of patent needs to monitor the encapsulation situation in the first encapsulation stage, and also needs to monitor the encapsulation situation after the suspension is mixed. The preparation steps are complicated and require many monitoring links. In the actual production process, not only is the preparation process long, but it also requires a lot of manpower and material resources. In view of this, the present invention proposes a method for preparing a microcapsule suspension containing oxyfluorfen. Summary of the invention

[0011] The invention provides a method for preparing a microcapsule suspension containing oxyfluorfen, which solves the problem of complicated preparation process of the microcapsule suspension containing oxyfluorfen in the prior art.

[0012] The technical scheme of the present invention is as follows: A method for preparing a microcapsule suspension containing oxyfluorfen, comprising the following steps:

[0013] S1: mixing oxyfluorfen with a dispersant, an organic solvent and water, stirring and dispersing the mixture sufficiently to obtain a mixture, and then shearing the mixture by a high-speed shearing method to obtain a stable oxyfluorfen suspension;

[0014] S2: mixing the oxyfluorfen suspension, emulsifier and water in S1 to obtain solution A;

[0015] S3: mixing the oil phase wall material, the microencapsulated agent and the organic solvent to obtain solution B, and then mixing the water phase wall material and water to obtain solution C;

[0016] S4: adding solution B in S3 dropwise to solution A, stirring and shearing the solution during the adding process until solution B and solution A are completely mixed to obtain a mixed solution;

[0017] S5: Solution C is continuously added dropwise to the mixed solution in S4, and stirring is performed during the adding process to obtain a stable oxyfluorfen microcapsule suspension.

[0018] Preferably, in S1, the organic solvent is one or more of toluene, xylene, methyl oleate and solvent oil, and the dispersant is one or more of polyvinyl pyrrolidone, sodium polyacrylate and polycarboxylate.

[0019] Preferably, in S2, the emulsifier is one or more of sodium lignin sulfonate, sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, styrene-maleic anhydride copolymer, fatty alcohol polyoxyethylene ether, and sorbitan polyoxyethylene polyoxypropylene ether.

[0020] Preferably, in S2, the ratio of the oxyfluorfen suspension, the emulsifier and the water in the solution A is (2-12):1:(1-10).

[0021] Preferably, in S3, the oil phase wall material is one or more of monoisocyanate, diisocyanate and polyisocyanate, and the water phase wall material is one or more of ethylenediamine, propylenetriamine, triethylenetetramine and triethylenediamine.

[0022] Preferably, in S3, the organic solvent is one or more of ethyl acetate, methyl oleate, xylene and solvent oil.

[0023] Preferably, in S3, the microencapsulated agent is any one of S-isopropylamine, acetochlor, alachlor, and pendimethalin.

[0024] Preferably, in S4, the ratio of the oil phase wall material, the microencapsulated agent and the organic solvent in the solution B is 1:(1-40):(1-5), and the ratio of the water phase wall material and water in the solution C is 1:(9-10).

[0025] Preferably, in S1, the specific process of the mixture through the high-speed shearing method is as follows:

[0026] (1) putting oxyfluorfen, a dispersant, an organic solvent and water into a preparation kettle and mixing them thoroughly to obtain a mixture;

[0027] (2) Then, a high-speed shearing machine is started to shear the mixture, and the speed of the shearing machine is 300 to 11,000 rp / min, so that the oxyfluorfen, dispersant, and organic solvent are fully dispersed and dissolved in water, ensuring that 98% of the particle size in the mixture is less than 8 microns, and a stable oxyfluorfen suspension is obtained.

[0028] Preferably, in S5, the stirring condition is 250-300 rpm, and the stirring time is 50-60 minutes.

[0029] The working principle and beneficial effects of the present invention are as follows: In the present invention, oxyfluorfen is prepared into an oxyfluorfen suspension, which is mixed with an emulsifier to obtain solution A. Then, solution B containing an oil-phase wall material and a microencapsulatable agent and solution C containing a water-phase wall material are added in sequence, thereby directly preparing a mixed microcapsule suspension containing two active ingredients, simplifying the preparation process of oxyfluorfen microcapsules and effectively reducing the preparation cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present invention will be further described in detail below in conjunction with the drawings and specific embodiments.

[0031] Figure 1 It is a table of the thermal storage stability of the microcapsule suspension of oxyfluorfen in each group of Experimental Test Example 1 of the present invention;

[0032] Figure 2 It is a table of the low-temperature stability of the microcapsule suspension of oxyfluorfen in each group of Experimental Test Example 2 of the present invention;

[0033] Figure 3 It is a table of the plant control efficacy in different time periods in each treatment area of Experimental Test Example 3 of the present invention. SPECIFIC EMBODIMENTS

[0034] 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 the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of the present invention.

[0035] The present invention provides a method for preparing a microcapsule suspension containing oxyfluorfen. A method for preparing a microcapsule suspension containing oxyfluorfen includes the following steps:

[0036] S1: Mix oxyfluorfen with a dispersant, an organic solvent and water, stir and disperse thoroughly to obtain a mixture, and then shear the mixture by high-speed shearing to obtain a stable oxyfluorfen suspension;

[0037] S2: Mix the oxyfluorfen suspension in S1, an emulsifier and water to obtain solution A;

[0038] S3: Mix an oil-phase wall material, a microencapsulatable agent and an organic solvent to obtain solution B, and then mix a water-phase wall material and water to obtain solution C;

[0039] S4: Drop solution B in S3 into solution A, and stir and shear during the dropping process until solution B and solution A are completely mixed to obtain a mixed solution;

[0040] S5: Solution C is continuously added dropwise to the mixed solution in S4, and stirring is performed during the adding process to obtain a stable oxyfluorfen microcapsule suspension.

[0041] In the present invention, oxyfluorfen is prepared into an oxyfluorfen suspension, which is mixed with an emulsifier to obtain a solution A, and then a solution B containing an oil phase wall material and a microencapsulated medicament and a solution C containing an aqueous phase wall material are sequentially added, thereby directly preparing a mixed microcapsule suspension containing two active ingredients at the same time, simplifying the preparation process of the oxyfluorfen microcapsule suspension and effectively reducing the preparation cost.

[0042] Furthermore, in S1, the organic solvent is one or more of toluene, xylene, methyl oleate and solvent oil, and the dispersant is one or more of polyvinyl pyrrolidone, sodium polyacrylate and polycarboxylate.

[0043] Furthermore, in S2, the emulsifier is one or more of sodium lignin sulfonate, sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, styrene-maleic anhydride copolymer, fatty alcohol polyoxyethylene ether, and sorbitan polyoxyethylene polyoxypropylene ether.

[0044] Furthermore, in S2, the ratio of the oxyfluorfen suspension, the emulsifier and the water in the solution A is (2-12):1:(1-10).

[0045] Further, in S3, the oil phase wall material is one or more of monoisocyanate, diisocyanate, and polyisocyanate, and the water phase wall material is one or more of ethylenediamine, propylenetriamine, triethylenetetramine, and triethylenediamine.

[0046] Further, in S3, the organic solvent is one or more of ethyl acetate, methyl oleate, xylene and solvent oil.

[0047] Further, in S3, the microencapsulated agent is any one of S-isopropylamine, acetochlor, alachlor, and pendimethalin.

[0048] Furthermore, in S4, the ratio of the oil phase wall material, the microencapsulated agent and the organic solvent in the solution B is 1:(1-40):(1-5), and the ratio of the water phase wall material and water in the solution C is 1:(9-10).

[0049] Further, in S1, the specific process of the mixture through the high-speed shearing method is as follows:

[0050] (1) placing oxyfluorfen, a dispersant, an organic solvent and water into a preparation kettle and mixing them thoroughly to obtain a mixture;

[0051] (2) Then start the high-speed shearer to shear the mixture. The rotation speed of the shearer is 300 - 11000 rp / min, so that oxyfluorfen, dispersant, and organic solvent are fully dispersed and dissolved in water, ensuring that 98% of the particle size in the mixture is less than 8 microns, and a stable oxyfluorfen suspension is obtained.

[0052] Further, in S5, the stirring conditions are 250 - 300 revolutions per minute, and the stirring time is 50 - 60 minutes.

[0053] Example 1:

[0054] This example provides a preparation method of a microcapsule suspension containing oxyfluorfen, including the following steps:

[0055] S1: Mix 35 wt% oxyfluorfen, 5 wt% polyvinylpyrrolidone, 3 wt% solvent oil, and 20 wt% water, fully stir and disperse to obtain a mixture, and then shear the mixture by the high-speed shear method. Among them, the rotation speed of the shearer is 2000 rp / min to obtain a stable oxyfluorfen suspension;

[0056] S2: Mix the oxyfluorfen suspension in S1, sodium lignosulfonate, and water to obtain solution A. Among them, the ratio of the oxyfluorfen suspension, sodium lignosulfonate, and water in solution A is 2:1:8.

[0057] S3: Mix monoisocyanate, S-metolachlor, and xylene to obtain solution B. Among them, the ratio of monoisocyanate, S-metolachlor, and xylene in solution B is 1:30:3. Then mix ethylenediamine and water to obtain solution C. Among them, the ratio of ethylenediamine and water in solution C is 1:9.

[0058] S4: Drop solution B in S3 into solution A, and stir and shear during the dropping process until solution B and solution A are completely mixed to obtain a mixed solution;

[0059] S5: Continue to drop solution C into the mixed solution in S4, and stir during the dropping process. The stirring conditions are 250 revolutions per minute, and the stirring time is 60 minutes to obtain a stable oxyfluorfen microcapsule suspension.

[0060] Example 2:

[0061] This example provides a preparation method of a microcapsule suspension containing oxyfluorfen, including the following steps:

[0062] S1: 35 wt% of oxyfluorfen, 5 wt% of sodium polyacrylate, 3 wt% of solvent oil and 20 wt% of water are mixed, fully stirred and dispersed to obtain a mixture, and then the mixture is sheared by a high-speed shearing method, wherein the speed of the shearing machine is 2000 rp / min, to obtain a stable oxyfluorfen suspension;

[0063] S2: The oxyfluorfen suspension, sodium lauryl sulfate and water in S1 are mixed to obtain a solution A, wherein the ratio of the oxyfluorfen suspension, sodium lauryl sulfate and water in the solution A is 3:1:9.

[0064] S3: Monoisocyanate, S-isopropylamine and xylene are mixed to obtain solution B, wherein the ratio of monoisocyanate, S-isopropylamine and xylene in solution B is 1:32:5; ethylenediamine and water are then mixed to obtain solution C, wherein the ratio of propylenetriamine and water in solution C is 1:9.

[0065] S4: adding solution B in S3 dropwise to solution A, stirring and shearing the solution during the adding process until solution B and solution A are completely mixed to obtain a mixed solution;

[0066] S5: Solution C is continuously added dropwise to the mixed solution in S4, with stirring performed during the adding process. The stirring condition is 280 rpm and the stirring time is 55 minutes, to obtain a stable oxyfluorfen microcapsule suspension.

[0067] Embodiment three:

[0068] This embodiment provides a method for preparing a microcapsule suspension containing oxyfluorfen, comprising the following steps:

[0069] S1: 35 wt% of oxyfluorfen, 5 wt% of polyvinyl pyrrolidone, 3 wt% of toluene and 20 wt% of water are mixed, stirred and dispersed to obtain a mixture, and then the mixture is sheared by a high-speed shearing method, wherein the speed of the shearing machine is 3000 rp / min, to obtain a stable oxyfluorfen suspension;

[0070] S2: The oxyfluorfen suspension, sodium lauryl sulfate and water in S1 are mixed to obtain a solution A, wherein the ratio of the oxyfluorfen suspension, sodium lauryl sulfate and water in the solution A is 3:1:9.

[0071] S3: Monoisocyanate, S-isopropylamine and xylene are mixed to obtain solution B, wherein the ratio of monoisocyanate, S-isopropylamine and xylene in solution B is 1:40:5; ethylenediamine and water are then mixed to obtain solution C, wherein the ratio of triethylenetetramine and water in solution C is 1:10.

[0072] S4: Add solution B in S3 dropwise to solution A, while stirring and shearing during the dropping process until solution B and solution A are completely mixed to obtain a mixed solution.

[0073] S5: Continuously add solution C to the mixed solution in S4, while stirring during the dropping process. The stirring condition is 300 revolutions per minute and the stirring time is 50 minutes to obtain a stable oxyfluorfen microcapsule suspension.

[0074] Example 4:

[0075] This example provides a method for preparing an oxyfluorfen microcapsule suspension, including the following steps:

[0076] S1: Mix 35 wt% oxyfluorfen, 5 wt% sodium polyacrylate, 3 wt% toluene and 20 wt% water, fully stir and disperse to obtain a mixture, and then shear the mixture by high-speed shearing method. Among them, the rotation speed of the shearing machine is 3000 rp / min to obtain a stable oxyfluorfen suspension.

[0077] S2: Mix the oxyfluorfen suspension in S1, sodium dodecyl sulfate and water to obtain solution A. Among them, the ratio of the oxyfluorfen suspension, sodium dodecyl sulfate and water in solution A is 3:1:9.

[0078] S3: Mix monoisocyanate, S-metolachlor and xylene to obtain solution B. Among them, the ratio of monoisocyanate, S-metolachlor and xylene in solution B is 1:40:5. Then mix ethylenediamine and water to obtain solution C. Among them, the ratio of triethylenetetramine and water in solution C is 1:10.

[0079] S4: Add solution B in S3 dropwise to solution A, while stirring and shearing during the dropping process until solution B and solution A are completely mixed to obtain a mixed solution.

[0080] S5: Continuously add solution C to the mixed solution in S4, while stirring during the dropping process. The stirring condition is 300 revolutions per minute and the stirring time is 50 minutes to obtain a stable oxyfluorfen microcapsule suspension.

[0081] Comparative Example 1:

[0082] This comparative example provides a method for preparing an oxyfluorfen microcapsule suspension, including the following steps:

[0083] S1: Mix 35 wt% oxyfluorfen, 5 wt% polyvinylpyrrolidone, 3 wt% solvent oil and 20 wt% water, fully stir and disperse to obtain a mixture, and then shear the mixture by high-speed shearing method. Among them, the rotation speed of the shearing machine is 2000 rp / min to obtain a stable oxyfluorfen suspension.

[0084] S2: The oxyfluorfen suspension, sodium lignin sulfonate and water in S1 are mixed to obtain a solution A, wherein the ratio of the oxyfluorfen suspension, sodium lignin sulfonate and water in the solution A is 2:1:8.

[0085] S3: Monoisocyanate, S-isopropylamine and xylene are mixed to obtain solution B, wherein the ratio of monoisocyanate, S-isopropylamine and xylene in solution B is 1:30:3; ethylenediamine and water are then mixed to obtain solution C, wherein the ratio of ethylenediamine and water in solution C is 1:9.

[0086] S4: adding solution C in S3 dropwise to solution A, stirring and shearing the solution during the adding process until solution C and solution A are completely mixed to obtain a mixed solution;

[0087] S5: Solution B is continuously added dropwise to the mixed solution in S4, with stirring performed during the dropping process. The stirring condition is 250 rpm and the stirring time is 60 minutes, to obtain a stable oxyfluorfen microcapsule suspension.

[0088] Comparative Example 2:

[0089] The only difference between this comparative example and Example 1 is that xylene is not used in the process of preparing solution B, and solution B is obtained directly by mixing monoisocyanate and S-isopropylamine. The ratio of monoisocyanate to S-isopropylamine in solution B is 1:30.

[0090] Comparative Example 3:

[0091] The only difference between this comparative example and Example 1 is that solution B is added dropwise to solution A, and only stirring is started without shearing.

[0092] Comparative Example 4:

[0093] The only difference between this comparative example and Example 1 is that solution B is added dropwise to solution A, and only shearing is started without stirring.

[0094] Comparative Example 5:

[0095] The only difference between this comparative example and Example 1 is that the method of Example 1 is used to prepare only the oxyfluorfen suspension, and the specific steps are as follows:

[0096] 35 wt% of oxyfluorfen, 5 wt% of polyvinyl pyrrolidone, 3 wt% of solvent oil and 20 wt% of water are mixed, stirred and dispersed to obtain a mixture, and then the mixture is sheared by a high-speed shearing method, wherein the rotation speed of the shearing machine is 2000 rp / min, to obtain a stable oxyfluorfen suspension.

[0097] Experimental test example 1:

[0098] This test example is used to test the thermal storage stability of the microcapsule suspension of oxyfluorfen obtained in Example 1, Example 2, Example 3, Example 4, Comparative Example 1, Comparative Example 2, Comparative Example 3, and Comparative Example 4.

[0099] Among them, the specific steps of the thermal storage stability test are as follows: The microcapsule suspensions of oxyfluorfen obtained in Example 1, Example 2, Example 3, Example 4, Comparative Example 1, Comparative Example 2, Comparative Example 3, and Comparative Example 4 are respectively filled into containers, sealed and placed in a constant temperature oven at (54 ± 2) °C. After standing for 14 days, they are taken out. According to the GB / T14825-2006 standard, the suspension rate is measured. The results are as Figure 1 shown;

[0100] As can be seen from Figure 1 this, the microcapsule suspension of oxyfluorfen provided by the present invention has good thermal storage stability;

[0101] Experimental Test Example 2:

[0102] This test example is used to test the low-temperature stability of the microcapsule suspension of oxyfluorfen obtained in Example 1, Example 2, Example 3, Example 4, Comparative Example 1, Comparative Example 2, Comparative Example 3, and Comparative Example 4.

[0103] The specific steps for measuring the low-temperature stability are as follows: The microcapsule suspensions of oxyfluorfen obtained in Example 1, Example 2, Example 3, Example 4, Comparative Example 1, Comparative Example 2, Comparative Example 3, and Comparative Example 4 are respectively filled into containers, sealed and placed in a refrigerator at (0 ± 2) °C for 1 h. Stir once every 15 min for 15 s each time, observe whether there is any change in appearance, continue to place it at (0 ± 2) °C for 7 days, and then take it out and place it at room temperature to stand and recover. According to the GB / T14825-2006 standard, the suspension rate is measured. The results are as Figure 2 shown;

[0104] Experimental Test Example 3:

[0105] This test example is used to test the control effect of the medicaments obtained in Example 1, Example 2, Example 3, Example 4, Comparative Example 1, Comparative Example 2, Comparative Example 3, Comparative Example 4, Comparative Example 5, and Comparative Example 6 on barnyard grass in corn fields. Before the test, each medicament is diluted with distilled water to an aqueous solution with an effective active ingredient concentration of 0.1 wt%.

[0106] Experimental location: Shijiazhuang City, Hebei Province. The terrain of this plot is flat and the fertility is good. The corn in each treatment area after spraying is managed according to conventional production.

[0107] The specific spraying process of the corn in each treatment area is as follows:

[0108] First, use a knapsack sprayer to evenly spray the medicaments obtained in Example 1, Example 2, Example 3, Example 4, Comparative Example 1, Comparative Example 2, Comparative Example 3, Comparative Example 4, and Comparative Example 5 on the corn fields in each planting area at a dosage of 30 g / mu before emergence after sowing, and set a clear water control;

[0109] Then, investigate the control effects of barnyard grass 10 days, 20 days, 30 days, and 50 days after spraying. The specific test method is carried out in accordance with the "Guidelines for Field Efficacy Trials of Pesticides". Five random sampling points are used in each treatment area to investigate the control effects of barnyard grass plants in each treatment area. At 10, 20, 30, and 50 days after spraying, identify and count the barnyard grass, and calculate the plant control efficacy according to the following formula:

[0110]

[0111] Specific results Figure 3 。

[0112] From Figure 2 It can be seen that the microcapsule suspension of oxyfluorfen prepared by the preparation method provided by the present disclosure under specific reaction conditions such as stirring speed, emulsifying dispersant, and solvent can achieve the effect of slowly releasing and long-acting control of various weeds in crops.

[0113] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A preparation method of a microcapsule suspension containing oxyfluorfen, characterized in that, The steps include: S1: mixing oxyfluorfen with a dispersant, an organic solvent and water, stirring and dispersing the mixture sufficiently to obtain a mixture, and then shearing the mixture by a high-speed shearing method to obtain a stable oxyfluorfen suspension; S2: mixing the oxyfluorfen suspension, emulsifier and water in S1 to obtain solution A; S3: mixing the oil phase wall material, the microencapsulated agent and the organic solvent to obtain solution B, and then mixing the water phase wall material and water to obtain solution C; S4: adding solution B in S3 dropwise to solution A, stirring and shearing the solution during the adding process until solution B and solution A are completely mixed to obtain a mixed solution; S5: Solution C is continuously added dropwise to the mixed solution in S4, and stirring is performed during the adding process to obtain a stable oxyfluorfen microcapsule suspension.

2. The preparation method of a microcapsule suspension containing oxyfluorfen according to claim 1, characterized in that, In S1, the organic solvent is one or more of toluene, xylene, methyl oleate and solvent oil, and the dispersant is one or more of polyvinyl pyrrolidone, sodium polyacrylate and polycarboxylate.

3. The preparation method of a microcapsule suspension containing oxyfluorfen according to claim 1, characterized in that, In S2, the emulsifier is one or more of sodium lignin sulfonate, sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, styrene-maleic anhydride copolymer, fatty alcohol polyoxyethylene ether, and sorbitan polyoxyethylene polyoxypropylene ether.

4. The preparation method of a microcapsule suspension containing oxyfluorfen according to claim 1, characterized in that, In S2, the ratio of oxyfluorfen suspension, emulsifier and water in the solution A is (2-12):1:(1-10).

5. The preparation method of a microcapsule suspension containing oxyfluorfen according to claim 4, characterized in that, In S3, the oil phase wall material is one or more of monoisocyanate, diisocyanate, and polyisocyanate, and the water phase wall material is one or more of ethylenediamine, propylenetriamine, triethylenetetramine, and triethylenediamine.

6. The preparation method of a microcapsule suspension containing oxyfluorfen according to claim 5, characterized in that, In S3, the organic solvent is one or more of ethyl acetate, methyl oleate, xylene and solvent oil.

7. A method for preparing a microcapsule suspension containing oxyfluorfen according to claim 1, characterized in that, In S3, the microencapsulated agent is any one of S-isopropylamine, acetochlor, alachlor, and pendimethalin.

8. The preparation method of a microcapsule suspension containing oxyfluorfen according to claim 1, characterized in that, In S4, the ratio of the oil phase wall material, the microencapsulated agent and the organic solvent in the solution B is 1:(1-40):(1-5), and the ratio of the water phase wall material and water in the solution C is 1:(9-10).

9. The preparation method of a microcapsule suspension containing oxyfluorfen according to claim 1, characterized in that, In S1, the specific process of the mixture through the high-speed shear method is as follows: (1) placing oxyfluorfen, a dispersant, an organic solvent and water into a preparation kettle and mixing them thoroughly to obtain a mixture; (2) Then, a high-speed shearing machine is started to shear the mixture, and the speed of the shearing machine is 300 to 11,000 rp / min, so that the oxyfluorfen, dispersant, and organic solvent are fully dispersed and dissolved in water, ensuring that 98% of the particle size in the mixture is less than 8 microns, and a stable oxyfluorfen suspension is obtained.

10. The preparation method of a microcapsule suspension containing oxyfluorfen according to claim 1, characterized in that, In S5, the stirring condition is 250-300 rpm, and the stirring time is 50-60 minutes.

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