Saflufenacil compounded pyroxasulfone herbicide and preparation method thereof

Abstract

The invention discloses a saflufenacil compounded pyroxasulfone herbicide and a preparation method thereof, and belongs to the technical field of herbicides, the preparation method comprises the following steps: weighing raw materials, and adding sodium lignin sulfonate, amphiphilic chitosan and dibutyltin dilaurate into water to obtain a component A; mixing the active component, diisocyanate and an oily solvent to obtain a component B; the active components comprise pyroxasulfone and saflufenacil in a mass ratio of 1: (1-5); and adding the component B into the component A, adding aminated beta-cyclodextrin, mixing, homogenizing and emulsifying to obtain an emulsion, setting the temperature to be 30-70 DEG C, and stirring for 2-3 hours to obtain the saflufenacil compound sulfone herbicide. The problem that the physical stability and weeding effect of the herbicide are influenced by molecular structure difference after saflufenacil and pyroxasulfone are compounded and embedded is solved synergistically, and the compatibility of effective components is enhanced.

Description

Technical Field

[0001] This invention belongs to the field of herbicide technology, specifically relating to a compound herbicide of sulfadiazine and sulfonylpyrazine and its preparation method. Background Technology

[0002] The mechanism of action of sulfonylpyrazole: Sulfonylpyrazole is a cell division inhibitor that inhibits the biosynthesis of VLCFAs (very long side-chain fatty acids) (C20-C30) in plants, thereby hindering the growth of meristems and coleoptiles. After application, sulfonylpyrazole is absorbed by the young roots and shoots of weeds, inhibiting early seedling growth and destroying meristems and coleoptiles. It is mainly used on grasses in corn, soybean, and wheat fields.

[0003] Bensulfuron-methyl primarily exerts its effects by inhibiting protoporphyrinogen oxidase (PPO) in plants. PPO is a key enzyme in chlorophyll biosynthesis; its inhibition leads to the accumulation of protoporphyrinogen in the cytosol, triggering lipid peroxidation of the cell membrane. This reaction damages the structure and function of the cell membrane, causing cell leakage and tissue necrosis, ultimately resulting in plant death. Bensulfuron-methyl is a selective systemic herbicide that can be used for both pre-emergence and post-emergence treatments. It has foliar contact and soil residual activity, is rapidly absorbed by leaves and roots, and is quickly distributed throughout the plant via apoplastic and localized translocation through the phloem.

[0004] Bensulfuron has a good rapid effect, while sulfonylpyrazole has a longer residual effect. The combination of the two can balance the rapid and residual effects to a certain extent. However, bensulfuron contains sulfonamide groups, which are highly polar and easily soluble in water, while sulfonylpyrazole contains sulfonyl groups and pyrazole rings, which are relatively hydrophobic. The difference in molecular polarity between the two makes it difficult for them to form a uniform and stable mixture. After long-term storage, the two active ingredients may aggregate due to polarity incompatibility, resulting in hardening, clumping, or the formation of precipitates at the bottom that cannot be resuspended, thus rendering the product ineffective.

[0005] Even if the formulation itself is stable, problems may arise again when diluted with water to form a spray solution. Adding a high concentration of compound formulation to a large volume of water creates a new, more complex dilution system. The different solubility and stability behaviors of molecules with different polarities in water can lead to "flash precipitation": hydrophobic sulfonylpyrazine particles may rapidly aggregate and precipitate due to a sudden change in system polarity (entering a large aquatic environment). Flocculation can also occur: hydrophilic sulfonylpyrazine may flocculate due to changes in electrolytes or pH. Ultimately, this results in stratification or precipitation in the spray solution. If this is not detected in time and spraying continues, the active ingredient in the pesticide cannot be evenly distributed, leading to poor efficacy or even phytotoxicity. Summary of the Invention

[0006] The purpose of this invention is to provide a compound herbicide of pyrimethanil and sulfonylpyrazole and its preparation method, so as to solve the problem of poor mixing effect of pyrimethanil and sulfonylpyrazole.

[0007] The objective of this invention can be achieved through the following technical solutions: The first aspect of this application provides a method for preparing a compound herbicide of sulfonylpyrazine and sulfonylpyrazine, comprising the following steps: By weight, 3-4 parts of sodium lignosulfonate, 2-3 parts of amphiphilic chitosan, and 0.1-0.2 parts of dibutyltin dilaurate are added to 64-65 parts of water to obtain component A; 20-30 parts of active component, 3-4 parts of diisocyanate, and 40-45 parts of oily solvent are mixed to obtain component B; the active component includes sulfopyrazol and pyrimethanil in a mass ratio of 1:1-5.

[0008] Component B was added to component A, followed by the addition of aminoated β-cyclodextrin. The mixture was then homogenized and emulsified into an emulsion at 10,000-20,000 rpm. The temperature was set at 30-70℃, and the mixture was stirred for 2-3 hours at a stirring speed of 200-300 m / min to obtain a compound herbicide of sulfadiazine and sulfadiazine. Interfacial polymerization of diisocyanate and water under an organotin catalyst successfully prepared a polyurea-based wall material, which was then coated with sulfadiazine and sulfadiazine via polyurea-amphiphilic chitosan.

[0009] Furthermore, amphiphilic chitosan is prepared via the following steps: Chitosan was added to a 0.5% (w / w) acetic acid solution and stirred to disperse. Octenyl succinic anhydride was then added, with a chitosan-to-acetic acid ratio of 1g:20-30mL. The octenyl succinic anhydride was diluted with acetone before addition. The mixture was stirred and reacted at 20-30℃ for 4-5 hours. After the reaction, an alkali was added to adjust the system to neutral, and the mixture was concentrated under reduced pressure. The mixture was then precipitated with ethanol, washed, and vacuum dried at 40℃ to obtain amphiphilic chitosan. This amphiphilic chitosan is obtained by reacting chitosan and octenyl succinic anhydride with the amino groups in the chitosan structure to introduce hydrophilic carboxyl groups and hydrophobic long chains, resulting in an amphiphilic chitosan with excellent surface activity.

[0010] The hydroxyl groups in this amphiphilic chitosan can participate in the formation of the isocyanate cross-linking (existing polyurea network) structure. The hydrophobic structure in the amphiphilic chitosan can increase the density of the core (hydrophobic), reduce the fluidity of the core, reduce the thickness of the shell (wall material), improve the surface flexibility of the drug-loaded microcapsules, and improve the adhesion of herbicides to the leaves of weeds.

[0011] Amphiphilic chitosan can reduce the density and increase the thickness of the microcapsule shell. The introduction of amphiphilic chitosan can increase the content of hydroxyl groups and other easily hydrogen-bonding groups in the microcapsule shell (wall material), thereby improving the adhesion of the microcapsules to the leaf surface. This amphiphilic chitosan, reacted with chitosan and octenyl succinic anhydride to introduce amide segments, can improve the coating effect of two different types of herbicidal active ingredients, sulfadiazine and pyrimisulfuron. The polyurea wall material, with its dense cross-linked molecular structure and the introduction of amide bonds in the amphiphilic chitosan, effectively encapsulates the highly polar pyrimisulfuron, forming a diffusion barrier to delay its rapid initial dissolution and achieve slow release, thus meeting the needs of long-lasting herbicides.

[0012] The hydrophobic segments introduced into amphiphilic chitosan have good compatibility with hydrophobic sulfopyrazine, ensuring efficient encapsulation. At the same time, its ester / amide bonds can undergo slow degradation in the environment (chitosan is also an environmentally friendly material), providing a channel for the controlled and continuous release of active ingredients and ensuring the full exertion of the drug's efficacy.

[0013] Furthermore, the ratio of chitosan to octenyl succinic anhydride is 1 g: 0.008-0.01 mol. The chitosan (Mw = (1.0~2.0) × 10⁻⁶) 5 The degree of deacetylation is not less than 95%.

[0014] Furthermore, the diisocyanate is one of hexamethylene diisocyanate and diphenylmethane diisocyanate.

[0015] Furthermore, the oily solvent is one of corn oil, soybean oil, and aromatic solvent oil (150#, 200#).

[0016] Furthermore, the aminolated β-cyclodextrin is prepared by the following steps: Aminosilane coupling agent and β-cyclodextrin were added to an aqueous ethanol solution, ultrasonically dispersed, and stirred for 12 hours at a temperature of 50-60℃. After the reaction was completed, the mixture was washed with ethanol and dried to obtain amino-modified β-cyclodextrin. The volume fraction of the aqueous ethanol solution was 90%.

[0017] Furthermore, the ratio of the aminosilane coupling agent to β-cyclodextrin is 1-5:1.

[0018] Furthermore, the aminosilane coupling agent is one of 3-aminopropyltriethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane, and N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane.

[0019] The second aspect of this application provides a herbicide combining pyrimisulfuron and sulfonylpyrazine, prepared using the method described above. Pyrimisulfuron and sulfonylpyrazine have different physicochemical properties. In this invention, aminated β-cyclodextrin is added to the homogenized emulsion, covalently embedding it into the polymer network of the capsule wall or participating in the in-situ inclusion of the active ingredient, increasing the crosslinking density of the microcapsules and improving the encapsulation efficiency. Aminated β-cyclodextrin reacts with raw materials such as diisocyanate to form a highly crosslinked "star-shaped" or "network-like" polymer structure. This structure significantly enhances the mechanical strength and toughness of the capsule wall, making the microcapsules less prone to rupture and adhesion, greatly improving physical stability, preventing crystallization during storage, ensuring the physical stability and efficacy uniformity of the formulation, and improving storage stability. Aminated β-cyclodextrin can increase the apparent polarity of the herbicide in this invention, making it easier to adhere to plant leaves or specific soil components, improving drug utilization and indirectly enhancing efficacy.

[0020] The beneficial effects of this invention are: This invention provides a herbicide combining pyrimisulfuron and sulfonylpyrazine. The herbicidal effect is improved by combining pyrimisulfuron and sulfonylpyrazine. In the preparation process, this invention selects a polyurea-amphiphilic chitosan-cyclodextrin composite wall material system to synergistically solve the problem of the difference in molecular structure between pyrimisulfuron and sulfonylpyrazine after encapsulation, which affects the physical stability and herbicidal effect of the herbicide, and further enhances the compatibility of the active ingredients.

[0021] The polyurea-amyrophilic chitosan-cyclodextrin composite wall material system of this invention achieves effective encapsulation of pyrimethanil and sulfonylpyrazole, avoiding the impact of the polarity difference between pyrimethanil and sulfonylpyrazole on the adhesion of the microcapsules and ensuring the efficacy of the herbicides. In terms of safety, the cyclodextrin and chitosan used in this invention are both natural biodegradable molecules, promoting the biodegradation of the entire capsule wall. Detailed Implementation

[0022] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0023] Obviously, the following description is merely some examples or embodiments of this application. Those skilled in the art can apply this application to other similar scenarios without any inventive effort. Furthermore, it is understood that although the effort involved in such development may be complex and lengthy, for those skilled in the art related to the content disclosed in this application, any changes to design, manufacturing, or production based on the technical content disclosed in this application are merely conventional technical means and should not be construed as insufficient disclosure of the content of this application.

[0024] However, there may be instances where unnecessary detailed descriptions are omitted. For example, detailed descriptions of well-known matters or repetitive descriptions of essentially the same structure may be omitted. This is to avoid making the following description unnecessarily lengthy and to facilitate understanding by those skilled in the art. Furthermore, the following description is provided to enable those skilled in the art to fully understand this application and is not intended to limit the subject matter of the claims.

[0025] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions, and all technical features and optional technical features of this application can be combined to form new technical solutions.

[0026] The following is a detailed description of a compound herbicide of pyrimisulfuron and sulfonylpyrazine, and its preparation method, based on embodiments of this application.

[0027] The following is a detailed description with reference to specific examples.

[0028] Example 1

[0029] This embodiment provides a method for preparing a compound herbicide of sulfonylpyrazine and sulfonylpyrazine, comprising the following steps: By weight, 3 parts sodium lignosulfonate, 2 parts amphiphilic chitosan, and 0.1 parts dibutyltin dilaurate were added to 64 parts water to obtain component A; 20 parts of the active component, 3 parts of diisocyanate, and 40 parts of oily solvent were mixed to obtain component B; the active component included sulfonylpyrazol and pyrimisulfuron in a mass ratio of 1:1. The oily solvent was corn oil, and the diisocyanate was hexamethylene diisocyanate. Component B was added to component A, and aminoated β-cyclodextrin was added. After mixing, the mixture was homogenized and emulsified into an emulsion at a speed of 10,000 rpm. The temperature was set at 30℃, and the mixture was stirred for 3 hours at a stirring speed of 300 rpm to obtain the herbicide sulfadiazine combined with sulfadiazine.

[0030] Amphiphilic chitosan is prepared through the following steps: Chitosan was added to a 0.5% (w / w) acetic acid solution and stirred to disperse. Octenyl succinic anhydride was then added, with a chitosan to 0.5% (w / w) acetic acid ratio of 1 g: 20 mL. Octenyl succinic anhydride was diluted with acetone before addition. The mixture was stirred at 20°C for 4 hours. After the reaction, an alkali was added to adjust the system to neutral, and the mixture was concentrated under reduced pressure. The mixture was then precipitated with ethanol, washed, and dried under vacuum at 40°C to obtain amphiphilic chitosan. The chitosan to octenyl succinic anhydride ratio was 1 g: 0.009 mol. (Chitosan Mw = (1.0) × 10...) 5 The degree of deacetylation is not less than 95%.

[0031] The aminolated β-cyclodextrin is prepared by the following steps: An aminosilane coupling agent and β-cyclodextrin were added to an aqueous ethanol solution, ultrasonically dispersed, and then stirred at 60°C for 12 hours. After the reaction, the mixture was washed with ethanol and dried to obtain amino-modified β-cyclodextrin. The volume fraction of the aqueous ethanol solution was 90%. The ratio of the aminosilane coupling agent to β-cyclodextrin was 1:1. The aminosilane coupling agent was 3-aminopropyltriethoxysilane.

[0032] Example 2

[0033] This embodiment provides a method for preparing a compound herbicide of sulfonylpyrazine and sulfonylpyrazine, comprising the following steps: By weight, 4 parts sodium lignosulfonate, 3 parts amphiphilic chitosan, and 0.2 parts dibutyltin dilaurate were added to 65 parts water to obtain component A; 30 parts of the active component, 4 parts of diisocyanate, and 45 parts of oily solvent were mixed to obtain component B; the active component included sulfonylpyrazol and pyrimisulfuron in a mass ratio of 1:1. The oily solvent was corn oil, and the diisocyanate was hexamethylene diisocyanate.

[0034] Component B was added to component A, and aminoated β-cyclodextrin was added. After mixing, the mixture was homogenized and emulsified into an emulsion at a speed of 10,000 rpm. The temperature was set at 30℃, and the mixture was stirred for 3 hours at a stirring speed of 300 rpm to obtain the herbicide sulfadiazine combined with sulfadiazine.

[0035] The amphiphilic chitosan is the same as in Example 1.

[0036] The aminolated β-cyclodextrin is the same as in Example 1.

[0037] Example 3

[0038] This embodiment provides a method for preparing a compound herbicide of sulfonylpyrazine and sulfonylpyrazine, comprising the following steps: By weight, 3 parts sodium lignosulfonate, 2 parts amphiphilic chitosan, and 0.1 parts dibutyltin dilaurate were added to 64 parts water to obtain component A; 20 parts of the active component, 3 parts of diisocyanate, and 40 parts of oily solvent were mixed to obtain component B; the active component included sulfonylpyrazol and pyrimisulfuron in a mass ratio of 1:1. The oily solvent was corn oil, and the diisocyanate was hexamethylene diisocyanate.

[0039] Component B was added to component A, and aminoated β-cyclodextrin was added. After mixing, the mixture was homogenized and emulsified into an emulsion at a speed of 10,000 rpm. The temperature was set at 30℃, and the mixture was stirred for 3 hours at a stirring speed of 300 rpm to obtain the herbicide sulfadiazine combined with sulfadiazine.

[0040] The amphiphilic chitosan is the same as in Example 1.

[0041] The aminolated β-cyclodextrin is the same as in Example 1.

[0042] Example 4

[0043] This embodiment provides a method for preparing a compound herbicide of sulfonylpyrazine and sulfonylpyrazine, comprising the following steps: By weight, 3 parts sodium lignosulfonate, 2 parts amphiphilic chitosan, and 0.1 parts dibutyltin dilaurate were added to 64 parts water to obtain component A; 20 parts of the active component, 3 parts of diisocyanate, and 40 parts of oily solvent were mixed to obtain component B; the active component included sulfonylpyrazol and pyrimisulfuron in a mass ratio of 1:1. The oily solvent was corn oil, and the diisocyanate was diphenylmethane diisocyanate. Component B was added to component A, and aminoated β-cyclodextrin was added. After mixing, the mixture was homogenized and emulsified into an emulsion at a speed of 10,000 rpm. The temperature was set at 70℃, and the mixture was stirred for 3 hours at a stirring speed of 300 rpm to obtain the herbicide sulfadiazine combined with sulfadiazine.

[0044] The amphiphilic chitosan is the same as in Example 1.

[0045] The aminolated β-cyclodextrin is the same as in Example 1.

[0046] Example 5

[0047] The difference between this embodiment and Example 1 is that the aminoated β-cyclodextrin is different, while the other raw materials and preparation process are the same as in Example 1.

[0048] Aminated β-cyclodextrin is prepared by the following steps: An aminosilane coupling agent and β-cyclodextrin were added to an ethanol-water solution, ultrasonically dispersed, and then stirred at 60°C for 12 hours. After the reaction, the mixture was washed with ethanol and dried to obtain amino-modified β-cyclodextrin. The volume fraction of the ethanol-water solution was 90%. The ratio of the aminosilane coupling agent to β-cyclodextrin was 1:1. The aminosilane coupling agent was N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane.

[0049] Example 6

[0050] The difference between this embodiment and Example 1 is that the aminoated β-cyclodextrin is different, while the other raw materials and preparation process are the same as in Example 1.

[0051] Aminated β-cyclodextrin is prepared by the following steps: An aminosilane coupling agent and β-cyclodextrin were added to an aqueous ethanol solution, ultrasonically dispersed, and then stirred at 60°C for 12 hours. After the reaction, the mixture was washed with ethanol and dried to obtain amino-modified β-cyclodextrin. The volume fraction of the aqueous ethanol solution was 90%. The ratio of the aminosilane coupling agent to β-cyclodextrin was 1:2. The aminosilane coupling agent was 3-aminopropyltriethoxysilane.

[0052] Example 7

[0053] The difference between this embodiment and Example 1 is that the aminoated β-cyclodextrin is different, while the other raw materials and preparation process are the same as in Example 1.

[0054] Aminated β-cyclodextrin is prepared by the following steps: An aminosilane coupling agent and β-cyclodextrin were added to an aqueous ethanol solution, ultrasonically dispersed, and then stirred at 60°C for 12 hours. After the reaction, the mixture was washed with ethanol and dried to obtain amino-modified β-cyclodextrin. The volume fraction of the aqueous ethanol solution was 90%. The ratio of the aminosilane coupling agent to β-cyclodextrin was 1:3. The aminosilane coupling agent was 3-aminopropyltriethoxysilane.

[0055] Example 8

[0056] The difference between this embodiment and Example 1 is that the aminoated β-cyclodextrin is different, while the other raw materials and preparation process are the same as in Example 1.

[0057] Aminated β-cyclodextrin is prepared by the following steps: An aminosilane coupling agent and β-cyclodextrin were added to an aqueous ethanol solution, ultrasonically dispersed, and then stirred at 60°C for 12 hours. After the reaction, the mixture was washed with ethanol and dried to obtain amino-modified β-cyclodextrin. The volume fraction of the aqueous ethanol solution was 90%. The ratio of the aminosilane coupling agent to β-cyclodextrin was 1:5. The aminosilane coupling agent was 3-aminopropyltriethoxysilane.

[0058] Comparative Example 1

[0059] Compared with Example 1, this comparative example replaces the amphiphilic chitosan with the nonionic surfactant dodecylphenol polyoxyethylene ether, while the other raw materials and preparation process remain the same as in Example 1.

[0060] Comparative Example 2

[0061] Compared with Example 1, this comparative example does not contain amino-modified β-cyclodextrin, but the other raw materials and preparation process are the same as in Example 1.

[0062] Comparative Example 3

[0063] Compared with Example 1, this comparative example replaces the amphiphilic chitosan with the nonionic surfactant dodecylphenol polyoxyethylene ether, does not add amino-modified β-cyclodextrin, and the remaining raw materials and preparation process are the same as in Example 1.

[0064] Comparative Example 4

[0065] This comparative example provides a method for preparing a compound herbicide of sulfadiazine and sulfonylpyrazine, comprising the following steps: By weight, 3 parts sodium lignosulfonate, 2 parts amphiphilic chitosan, and 0.1 parts dibutyltin dilaurate were added to 64 parts water to obtain component A; 20 parts of the active component, 3 parts of diisocyanate, and 40 parts of oily solvent were mixed to obtain component B; the active component included sulfonylpyrazol and pyrimisulfuron in a mass ratio of 1:1. The oily solvent was corn oil, and the diisocyanate was hexamethylene diisocyanate. Component B was added to component A, followed by the addition of aminated β-cyclodextrin. The mixture was then homogenized and emulsified into an emulsion at 10,000 rpm. The temperature was set at 30°C, and the mixture was stirred for 3 hours at a stirring speed of 300 rpm to obtain the herbicide combination of pyrimisulfuron and sulfopyrazine. The difference between this comparative example and Example 1 is the increased amount of aminated β-cyclodextrin; the remaining raw materials and preparation process are the same as in Example 1.

[0066] Test example: Performance tests were performed on Examples 1-8 and Comparative Examples 1-4; Thermal storage stability: tested according to GB / T 19136-2021 method; storage conditions were (54±2)℃ for 14 days, and the test was conducted at 25℃.

[0067] The results are shown in Table 1: Table 1

[0068] Referring to Table 1, and based on Example 1 and Comparative Examples 1-3, it can be seen that amphiphilic chitosan and amino-β-cyclodextrin can improve the thermal storage stability of the herbicide in this invention. According to Comparative Example 4, the amount of amino-β-cyclodextrin added should not be too much. Excessive addition of amino-β-cyclodextrin will lead to excessively high shell density, which is not conducive to the coating of active ingredients and affects its storage stability.

[0069] Efficacy Test: The samples prepared in Example 1 and Comparative Examples 1-4 were diluted with water. The dosage of the active ingredient was 300g per hectare. Application method: Foliar spraying during the vigorous growth period of weeds. Target herb: Barnyard grass. Water was used as a control. After application, the surface of the test material was allowed to air dry naturally before being transferred to an incubator for routine cultivation. Water was replenished daily by bottom irrigation to maintain soil moisture. The control efficacy was recorded at 28 and 56 days.

[0070] The formula for calculating the control effect is: Control effect = (Number of weeds in the control area - Number of weeds in the treatment area) / Number of weeds in the control area × 100%.

[0071] Table 2

[0072] As can be seen from Table 2, adjusting the introduction of amphiphilic chitosan and amino-β-cyclodextrin during the preparation of the herbicide can improve the weed control effect. The herbicide prepared by this invention has the advantages of rapid weed control and long-lasting effect.

[0073] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0074] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a compound herbicide of sulfonylsulfamethoxam and sulfonylpyrazine, characterized in that, Includes the following steps: Weigh the raw materials, add sodium lignosulfonate, amphiphilic chitosan and dibutyltin dilaurate to water to obtain component A; mix the active component, diisocyanate and oily solvent to obtain component B; the active component includes sulfonylpyrazole and bensulfuron-methyl, and the mass ratio of sulfonylpyrazole to bensulfuron-methyl is 1:1-5; Add component B to component A, add aminoated β-cyclodextrin, mix and homogenize to form an emulsion, set the temperature to 30-70℃, stir for 2-3 hours to obtain the herbicide sulfadiazine combined with sulfadiazine.

2. The preparation method of the herbicide compounded with sulfonylpyrazine according to claim 1, characterized in that, By weight, the raw materials include 3-4 parts sodium lignosulfonate, 2-3 parts amphiphilic chitosan, 0.1-0.2 parts dibutyltin dilaurate, 64-65 parts water; 20-30 parts active ingredient, 3-4 parts diisocyanate, 40-45 parts oily solvent and 2-3 parts aminolated β-cyclodextrin.

3. The preparation method of the herbicide compounded with sulfonylpyrazine according to claim 1, characterized in that, The amphiphilic chitosan was prepared by the following steps: Chitosan was added to an acetic acid solution and stirred to disperse. Octenyl succinic anhydride was then added after being diluted with acetone. The mixture was stirred and reacted at 20-30℃ for 4-5 hours. After the reaction was completed, an alkali was added to adjust the system to neutral. The mixture was concentrated under reduced pressure, precipitated with ethanol, washed, and dried under vacuum at 40℃ to obtain amphiphilic chitosan.

4. The preparation method of the herbicide compounded with sulfonylpyrazine according to claim 3, characterized in that, The ratio of chitosan to octenyl succinic anhydride is 1 g: 0.008-0.01 mol.

5. The preparation method of the herbicide compounded with sulfonylpyrazine according to claim 1, characterized in that, The diisocyanate is one of hexamethylene diisocyanate and diphenylmethane diisocyanate.

6. The preparation method of the herbicide compounded with sulfonylpyrazine according to claim 1, characterized in that, The oily solvent is one of corn oil, soybean oil, and aromatic solvent oil.

7. The preparation method of the herbicide compounded with sulfonylpyrazine according to claim 1, characterized in that, The aminolated β-cyclodextrin is prepared by the following steps: Aminosilane coupling agent and β-cyclodextrin were added to an aqueous ethanol solution, ultrasonically dispersed, and stirred for 12 hours at a temperature of 50-60℃. After the reaction was completed, the mixture was washed with ethanol and dried to obtain amino-modified β-cyclodextrin. The volume fraction of the aqueous ethanol solution was 90%.

8. The preparation method of the herbicide compounded with sulfonylpyrazine according to claim 7, characterized in that, The ratio of the aminosilane coupling agent to β-cyclodextrin is 1-5:

1.

9. The preparation method of the herbicide compounded with sulfonylpyrazine according to claim 7, characterized in that, The aminosilane coupling agent is one of 3-aminopropyltriethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane, and N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane.

10. A herbicide combining sulfadiazine and pyrazosulfuron, characterized in that, Prepared by the preparation method according to any one of claims 1-9.

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