Composite herbicide containing halauxifen-methyl and pyraclonil and preparation method thereof
By designing a core-shell structure of chlorpyrifos and bispyribac-methyl, the problem of poor safety of chlorpyrifos herbicides has been solved, achieving efficient and safe weed control, expanding the weed control spectrum and avoiding phytotoxicity.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-26
- Publication Date
- 2026-04-07
AI Technical Summary
Existing chloropyridine herbicides have problems such as poor safety and insignificant synergistic effects. In particular, they are prone to causing phytotoxicity to crops during application and their weed control spectrum is not comprehensive enough.
The compound herbicide using chlorpyrifos and bispyribac-sodium utilizes a core-shell structure design, with chlorpyrifos as the core and bispyribac-sodium as the shell. By leveraging the synergistic effect of their different mechanisms of action, microemulsion micelles are formed, controlling the drug release rate and avoiding the risk of phytotoxicity.
It significantly improves the control effect on weeds, expands the scope of application, enhances safety, avoids the risk of phytotoxicity, and improves the stability and efficiency of herbicides.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of herbicide technology, and in particular to a compound herbicide containing chlorpyrifos and bispyribac-sodium and its preparation method. Background Technology
[0002] In modern agricultural production, herbicides are indispensable plant protection tools. They can efficiently and quickly control weeds in the field, ensuring crop growth space and resources, significantly reducing the labor intensity and cost of manual weeding, and playing a key role in improving crop yield and quality. However, with the long-term, widespread, and even single-use use of chemical herbicides, weeds have gradually begun to develop resistance, leading to the elimination of many traditional herbicide active ingredients. Therefore, researching highly efficient herbicides with novel mechanisms of action and environmental friendliness is of great significance for the large-scale cultivation of major food crops.
[0003] Arylpyridine carboxylate herbicides, specifically chloropyridine esters, are a new generation of synthetic auxin-based herbicides. Chloropyridine esters can mimic high doses of plant auxins, interfering with the hormonal balance of sensitive plants, thereby inhibiting cell division and growth, ultimately leading to weed death. It also has a highly effective control effect on weeds that have developed resistance, and it has a broad spectrum of activity, effectively controlling the vast majority of field weeds.
[0004] However, chlorpyrifos, as the active ingredient in herbicides, has also revealed significant defects and limitations in practical applications. The most critical issue is its poor crop safety, easily causing phytotoxicity. Due to its potent hormonal effects, improper application conditions can easily damage crops themselves, such as causing leaf curling and inhibited growth. Furthermore, chlorpyrifos has a limited spectrum of activity, showing poor control of some important weeds, thus restricting its effectiveness as a single agent in fields with complex weed populations.
[0005] To overcome the aforementioned shortcomings of chloropyridinium ester, extend its service life, and enhance its integrated pest management capabilities in the field, existing technologies typically involve adding dedicated herbicide safeners to formulations to improve crop tolerance to chloropyridinium ester and thus reduce the risk of phytotoxicity. Alternatively, it can be compounded with other herbicidal active ingredients to improve weed control efficiency. However, the protective effect of safeners may affect the crop's growth stage and cannot completely eliminate the risk of phytotoxicity. Furthermore, common compound systems still face problems such as insufficient weed control spectrum, and the environment has a significant overall impact on their effectiveness. Therefore, obtaining a compound herbicide with significantly enhanced efficacy and higher safety is of great importance. Summary of the Invention
[0006] This invention provides a compound herbicide containing chlorpyrifos and bispyribac-methyl and its preparation method, which can solve the problems of poor safety and insignificant synergistic effect of chlorpyrifos herbicide in the prior art.
[0007] In a first aspect, the present invention provides a method for preparing a compound herbicide containing chlorpyrifos and bispyribac-sodium, comprising the following process steps: S1. Add chlorofluoropyridine ester, cyclohexanone and emulsifier to solvent oil, stir to dissolve and obtain oil phase; S2. Add a composite surfactant to the oil phase, stir and disperse, then add water and disperse and homogenize to obtain a microemulsion; S3. Add quaternized cyclodextrin to acetone, stir to disperse, then add bispyribac-sodium and synergist, and continue stirring to dissolve to obtain the organic phase; S4. Pour the organic phase into the microemulsion and perform high-speed shearing, then raise the temperature to 65-75℃ and continue stirring to volatilize. Finally, centrifuge, wash and dry to obtain the final product.
[0008] Preferably, the volume ratio of the organic phase to the microemulsion is 1:(6-8).
[0009] By adopting the above technical solution, the compound herbicide of the present invention uses chlorpyrifos and bispyribac-sodium for compounding. Chlorpyrifos, as a synthetic auxin herbicide, can simulate high doses of auxin, causing excessive cell division and growth disorder in sensitive weeds. Bispyribac-sodium mainly inhibits enzyme activity, destroys cell membranes, and interferes with the photosynthetic process of weeds. The two have different mechanisms of action and no cross-resistance. They can act on multiple different physiological processes of weeds. The synergy between the two can quickly inhibit weed competition by contact killing, produce a synergistic effect, significantly improve the control effect of weeds, and have complementary lineages, which can expand the types of weeds that can be controlled. The multi-target effect can greatly delay the rate at which weed populations develop resistance to a single agent.
[0010] The compound herbicide of this application has a core-shell structure. The core is composed of microemulsion micelles containing chlorpyrifos, and the outer layer is a cyclodextrin shell loaded with cyprodinil and a synergist. During application, cyprodinil in the shell is released rapidly and exerts its effect first, quickly causing lipid peroxidation of the cell membrane of sensitive weeds, producing a contact killing effect, leading to rapid necrosis and drying of the leaves. Then, chlorpyrifos in the core is slowly released through the shell, or the core is gradually absorbed. After being absorbed by the weeds, it is translocated to the meristematic tissue, further interfering with the hormone balance of the weeds, leading to weed death. It can produce synergistic effects against different weed populations, expand the scope of application for weeds, and improve the weed control efficiency.
[0011] Moreover, the core-shell structure of compound herbicides can physically isolate the chloropyridine ester in the core, preventing crops from directly contacting high concentrations of chloropyridine ester at the beginning of application. During application, the shell can also control the release rate of chloropyridine ester, keeping its effective concentration in the environment at the optimal level. This ensures the effective period while avoiding the risk of phytotoxicity from peak concentrations, thereby improving the safety of compound herbicides.
[0012] Preferably, the emulsifier includes one or a combination of two of Agricultural Emulsion No. 500 and Agricultural Emulsion No. 600.
[0013] Preferably, the oil phase comprises 1-2% by mass of chloropyridine ester, 6-9% by mass of cyclohexanone, 10-20% by mass of emulsifier, and the balance being solvent oil.
[0014] More preferably, the solvent oil is No. 150 solvent oil.
[0015] By adopting the above technical solution, the oil phase core of the microemulsion is prepared in step S1. Specifically, the solvent oil is used as the main solvent, which can fully dissolve the lipophilic chloropyridine ester technical material. The addition of the emulsifier can provide good interfacial stability, form a composite interfacial film, provide spatial stability for subsequent processing, and maintain the structural integrity and particle size uniformity of the oil core.
[0016] Cyclohexanone is also added during the process, which can effectively disrupt the molecular forces between the original drug crystals, greatly improve the solubility and stability of chlorofluoropyridine ester in the oil phase, and prevent precipitation during subsequent processing and storage. Moreover, cyclohexanone itself has certain surface activity, which can reduce the interfacial tension between the two phases and help disperse into smaller and more uniform droplets.
[0017] Preferably, the composite surfactant comprises an anionic surfactant and a co-surfactant in a mass ratio of 1:(0.5-1); the anionic surfactant comprises one or more of alkylbenzene sulfonic acid surfactants, alkyl sulfate surfactants and sulfosuccinate surfactants; the co-surfactant comprises one or more of n-butanol, n-pentanol, isopentanol, n-hexanol and n-octanol.
[0018] Preferably, the microemulsion comprises 15-20% by mass of an oil phase, 20-30% by mass of a composite surfactant, and the balance being water.
[0019] By adopting the above technical solution, after obtaining the oil phase, a composite surfactant and water are added. Under the action of stirring and homogenization, the surfactant molecules are oriented at the oil-water interface, encapsulating the oil phase into stable droplets with uniform particle size, forming an oil-in-water microemulsion, in which chlorofluoropyridine ester is encapsulated inside micelles.
[0020] Composite surfactants include anionic surfactants and co-surfactants. The synergistic effect of the two can greatly reduce the surface tension between oil and water, and promote the formation of thermodynamically stable microemulsions. Anionic surfactants carry a negative charge and can cause droplets to repel each other through electrostatic repulsion, thus dispersing them in the aqueous phase. At this time, the insertion of co-surfactants can enhance the mechanical strength of the interfacial film, forming a dense composite film that encapsulates chloropyridine ester and improves the overall stability.
[0021] Compared to ordinary emulsions, the microemulsion obtained by this invention has a stable structure and uniform particle size distribution, which can achieve high dispersion and controllable release of active pharmaceutical ingredient molecules, avoiding the precipitation problem of traditional emulsifiable concentrates, and providing an ideal liquid precursor for the subsequent preparation of herbicide particles with good stability and high efficacy.
[0022] Preferably, the raw materials for the quaternized cyclodextrin include β-cyclodextrin, epichlorohydrin, and organic amines in a mass ratio of 1:(0.75-0.85):(0.2-0.3); the organic amines include one or more combinations of triethylamine, trimethylamine, tripropylamine, N,N-dimethylethanolamine, and N,N-diethylethanolamine.
[0023] Preferably, the quaternized cyclodextrin is prepared according to the following method: β-Cyclodextrin was dispersed in water, an alkaline solution was added, the temperature was raised to 40-50°C, and the mixture was activated for 10-30 minutes. Then epichlorohydrin was added, and the reaction was continued with stirring for 7-8 hours. Finally, the pretreated cyclodextrin polymer was obtained by filtration, washing, and drying. The pretreated cyclodextrin polymer was swollen with water, and then an organic amine was added. The temperature was raised to 70-80°C, and the mixture was stirred for 6-8 hours. Finally, the product was obtained by filtration, washing, and drying.
[0024] More preferably, the alkaline solution includes an aqueous solution of sodium hydroxide.
[0025] Preferably, the organic phase comprises 2-5% by mass of quaternized cyclodextrin, 5-7% by mass of bispyribac-sodium, 0.5-2% by mass of synergist and the balance being acetone; The synergist includes one or more combinations of methylated vegetable oil and agricultural organosilicon synergist.
[0026] By employing the above technical solution, acetone, as a good organic solvent, can dissolve and disperse organic phase components. Quaternized cyclodextrin, as the main raw material of the shell layer, is also the main carrier material for bispyribac-sodium and the synergist. The organic phase is obtained through mixing and loading. Then, the organic phase is mixed with the microemulsion. Under high-speed shearing, the quaternized cyclodextrin loaded with bispyribac-sodium and the synergist is uniformly dispersed and adsorbed at the oil-water interface of the microemulsion droplets by electrostatic attraction. Then, the temperature is raised to volatilize the acetone. At this time, the quaternized cyclodextrin is deposited and solidified at the microemulsion droplet interface, forming a stable coating shell layer. Finally, a core-shell structured composite herbicide is obtained, with an oil core containing chloropyridinium ester as the core and quaternized cyclodextrin loaded with bispyribac-sodium as the shell.
[0027] The shell layer of this invention uses quaternized cyclodextrin. In the preparation process, the cyclodextrin is first activated. The alkaline solution can deprotonate the hydroxyl groups on the cyclodextrin molecule to obtain oxygen ions with higher activity. Epichlorohydrin is used as a crosslinking agent to react with oxygen ions to form cyclodextrin polymers, which can increase the strength and stability of the skeleton as a carrier material and introduce epoxy groups. Then, water is added to swell, which is conducive to the entry of organic amine molecules. The organic amine reacts with the epoxy groups to form quaternary ammonium groups.
[0028] The obtained quaternized cyclodextrin, on the one hand, in the preparation process of compound herbicides, the surface of the microemulsion droplets has a stable negative charge due to the presence of anionic surfactants, and the cyclodextrin after quaternization has a strong positive charge. The two generate a strong electrostatic attraction, thereby driving the quaternized cyclodextrin molecules to be rapidly adsorbed on the oil-water interface of the microemulsion droplets, completing the initial anchoring.
[0029] On the other hand, the hydrophobic cavity contained in the quaternized cyclodextrin is retained, which can encapsulate hydrophobic molecules of bispyribac-sodium and synergists through hydrophobic interactions and intermolecular interactions, thereby achieving effective loading of active ingredients and encapsulating drug molecules in the cavity, thereby improving physical drug loading and stability and preventing crystallization or premature precipitation.
[0030] Furthermore, synergists are introduced into the shell layer, which can significantly reduce the contact angle and surface tension of the active ingredients of the drug on the leaf surface of the target weeds, forming a uniform drug film, increasing the contact area, and assisting the active ingredients of the drug to penetrate the cuticle and stomata of the leaf, promoting the penetration of drug molecules and accelerating their effect in the plant.
[0031] Finally, as the temperature is increased, acetone is removed, disrupting the dissolved state. Quaternized cyclodextrin, already adsorbed at the microemulsion droplet interface, precipitates and solidifies at the interface due to decreased solubility, ultimately forming composite herbicide particles encapsulating the oil core. The core-shell structure effectively controls the release rate of the herbicide molecules. The shell layer of cyprodinil rapidly contacts and kills the herbicide, disrupting the leaf barrier, while the core layer of chlorpyrifos is slowly absorbed and translocated, thus increasing the overall killing speed, eradicating weeds, and improving safety. This results in a highly effective and safe composite herbicide.
[0032] Secondly, the present invention provides a compound herbicide containing chlorpyrifos and bispyribac-methyl, which is prepared according to the preparation method of the compound herbicide containing chlorpyrifos and bispyribac-methyl provided above.
[0033] The beneficial effects of this invention are: 1. The compound herbicide of the present invention uses chlorpyrifos and bispyribac-sodium for compounding. The two have different mechanisms of action and can act on multiple different physiological processes of weeds to achieve rapid contact killing and eradication of weeds, significantly improving the control effect of weeds. Moreover, they are complementary in their spectrum and can be applied to a variety of weed populations.
[0034] 2. The compound herbicide of the present invention has a core-shell structure, with an oil core containing chloropyridinium ester as the core and a quaternized cyclodextrin loaded with bispyribac-methyl as the shell. This structure can effectively control the release rate of the drug molecules. The bispyribac-methyl in the shell layer first rapidly contacts and kills the herbicide, destroying the leaf barrier. The chloropyridinium ester in the core layer is then slowly absorbed and transported through the body. This ensures the effective period while avoiding the risk of phytotoxicity from peak concentrations, improving the overall killing speed, eradicating weeds, and enhancing safety. This results in a compound herbicide that is highly effective and safe.
[0035] 3. The shell layer of the composite herbicide of the present invention uses quaternized cyclodextrin, which on the one hand can generate electrostatic attraction between itself and microemulsion droplets containing anionic surfactants, driving the quaternized cyclodextrin molecules to be rapidly adsorbed on the oil-water interface of the microemulsion droplets to form a uniform and structurally stable coating shell layer; on the other hand, the hydrophobic cavity it contains can encapsulate hydrophobic molecules loaded with bispyribac-sodium and synergists, thereby improving the drug loading capacity and stability. Detailed Implementation
[0036] The specific embodiments of the present invention will be described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.
[0037] Preparation Example
[0038] Preparation Example 1: A quaternized cyclodextrin was prepared according to the following method: 10g of β-cyclodextrin was dispersed in 50mL of water, 20mL of 1mol / L sodium hydroxide aqueous solution was added, the temperature was raised to 45℃ and activated for 30min, then 8g of epichlorohydrin was added, and the reaction was continued to be stirred for 8h. Finally, the pretreated cyclodextrin polymer was obtained by filtration, washing and drying. The pretreated cyclodextrin polymer was swollen with water, and then 2.5 g of triethylamine was added. The temperature was raised to 80 °C, and the mixture was stirred for 6 h. Finally, the product was obtained by filtration, washing, and drying.
[0039] Preparation Example 2, a quaternized cyclodextrin, differs from Preparation Example 1 only in that the amount of epichlorohydrin added is 7.5 g; and the amount of triethylamine added is 2 g.
[0040] Preparation Example 3, a quaternized cyclodextrin, differs from Preparation Example 1 only in that the amount of epichlorohydrin added is 8.5 g; and the amount of triethylamine added is 3 g.
[0041] Example
[0042] Example 1: A compound herbicide containing chlorpyrifos and bispyribac-methyl was prepared according to the following method: S1. Add chlorofluoropyridine ester, cyclohexanone, and an emulsifier obtained by mixing agricultural emulsion No. 500 and agricultural emulsion No. 600 in a mass ratio of 1:1 to solvent oil No. 150. After stirring and dissolving, an oil phase is obtained, wherein the oil phase includes 1.5% chlorofluoropyridine ester, 7% cyclohexanone, 15% emulsifier, and the balance being solvent oil No. 150. S2. Add a composite surfactant to the oil phase, wherein the composite surfactant is obtained by mixing sodium dodecylbenzenesulfonate and n-butanol in a mass ratio of 1:1, stirring and dispersing, then adding water, dispersing and homogenizing to obtain a microemulsion, wherein the microemulsion includes 20% oil phase, 30% composite surfactant and the balance water by mass fraction. S3. Add the quaternized cyclodextrin prepared in Preparation Example 1 to acetone, stir and disperse, then add bispyribac-sodium and methylated vegetable oil (model FB-71), and continue stirring to dissolve to obtain an organic phase, wherein the organic phase includes 4% quaternized cyclodextrin, 6% bispyribac-sodium, 1% methylated vegetable oil and the balance acetone by mass fraction. S4. The organic phase is poured into the microemulsion and subjected to high-speed shearing, wherein the volume ratio of the organic phase to the microemulsion is 1:7. Then the temperature is raised to 70°C and stirred continuously to volatilize. Finally, the product is obtained by centrifugation, washing and drying.
[0043] Example 2: A compound herbicide containing chlorpyrifos and bispyribac-methyl was prepared according to the following method: S1. Add chlorofluoropyridine ester, cyclohexanone, and an emulsifier obtained by mixing agricultural emulsion No. 500 and agricultural emulsion No. 600 in a mass ratio of 1:1 to solvent oil No. 150. After stirring and dissolving, an oil phase is obtained, wherein the oil phase includes 1% chlorofluoropyridine ester, 6% cyclohexanone, 10% emulsifier, and the balance being solvent oil No. 150. S2. Add a composite surfactant to the oil phase, wherein the composite surfactant is obtained by mixing sodium dodecylbenzenesulfonate and n-butanol in a mass ratio of 1:1, stirring and dispersing, then adding water, dispersing and homogenizing to obtain a microemulsion, wherein the microemulsion includes 20% oil phase, 30% composite surfactant and the balance water by mass fraction. S3. Add the quaternized cyclodextrin prepared in Preparation Example 1 to acetone, stir and disperse, then add bispyribac-sodium and methylated vegetable oil (model FB-71), and continue stirring to dissolve to obtain an organic phase, wherein the organic phase includes 4% quaternized cyclodextrin, 6% bispyribac-sodium, 1% methylated vegetable oil and the balance acetone by mass fraction. S4. The organic phase is poured into the microemulsion and subjected to high-speed shearing, wherein the volume ratio of the organic phase to the microemulsion is 1:8. Then the temperature is raised to 70°C and stirred continuously to volatilize. Finally, the product is obtained by centrifugation, washing and drying.
[0044] Example 3: A compound herbicide containing chlorpyrifos and bispyribac-methyl was prepared according to the following method: S1. Add chlorofluoropyridine ester, cyclohexanone, and an emulsifier obtained by mixing agricultural emulsion No. 500 and agricultural emulsion No. 600 in a mass ratio of 1:1 to solvent oil No. 150. After stirring and dissolving, an oil phase is obtained, wherein the oil phase includes 2% chlorofluoropyridine ester, 9% cyclohexanone, 20% emulsifier, and the balance being solvent oil No. 150. S2. Add a composite surfactant to the oil phase, wherein the composite surfactant is obtained by mixing sodium dodecylbenzenesulfonate and n-butanol in a mass ratio of 1:1, stirring and dispersing, then adding water, dispersing and homogenizing to obtain a microemulsion, wherein the microemulsion includes 15% oil phase, 20% composite surfactant and the balance water by mass fraction. S3. Add the quaternized cyclodextrin prepared in Preparation Example 1 to acetone, stir and disperse, then add bispyribac-sodium and methylated vegetable oil, continue stirring to dissolve and obtain an organic phase, wherein the organic phase includes 4% quaternized cyclodextrin, 6% bispyribac-sodium, 1% methylated vegetable oil and the balance acetone by mass fraction. S4. The organic phase is poured into the microemulsion and subjected to high-speed shearing, wherein the volume ratio of the organic phase to the microemulsion is 1:6. Then the temperature is raised to 70°C and stirred continuously to volatilize. Finally, the product is obtained by centrifugation, washing and drying.
[0045] Example 4: A compound herbicide containing chlorpyrifos and bispyribac-methyl was prepared according to the following method: S1. Add chlorofluoropyridine ester, cyclohexanone, and an emulsifier obtained by mixing agricultural emulsion No. 500 and agricultural emulsion No. 600 in a mass ratio of 1:1 to solvent oil No. 150. After stirring and dissolving, an oil phase is obtained, wherein the oil phase includes 1.5% chlorofluoropyridine ester, 7% cyclohexanone, 15% emulsifier, and the balance being solvent oil No. 150. S2. Add a composite surfactant to the oil phase, wherein the composite surfactant is obtained by mixing sodium dodecylbenzenesulfonate and n-butanol in a mass ratio of 1:1, stirring and dispersing, then adding water, dispersing and homogenizing to obtain a microemulsion, wherein the microemulsion includes 20% oil phase, 30% composite surfactant and the balance water by mass fraction. S3. Add the quaternized cyclodextrin prepared in Preparation Example 1 to acetone, stir and disperse, then add bispyribac-sodium and methylated vegetable oil (model FB-71), and continue stirring to dissolve to obtain an organic phase, wherein the organic phase includes 2% quaternized cyclodextrin, 5% bispyribac-sodium, 2% methylated vegetable oil and the balance acetone by mass fraction. S4. The organic phase is poured into the microemulsion and subjected to high-speed shearing, wherein the volume ratio of the organic phase to the microemulsion is 1:7. Then the temperature is raised to 70°C and stirred continuously to volatilize. Finally, the product is obtained by centrifugation, washing and drying.
[0046] Example 5: A compound herbicide containing chlorpyrifos and bispyribac-methyl was prepared according to the following method: S1. Add chlorofluoropyridine ester, cyclohexanone, and an emulsifier obtained by mixing agricultural emulsion No. 500 and agricultural emulsion No. 600 in a mass ratio of 1:1 to solvent oil No. 150. After stirring and dissolving, an oil phase is obtained, wherein the oil phase includes 1.5% chlorofluoropyridine ester, 7% cyclohexanone, 15% emulsifier, and the balance being solvent oil No. 150. S2. Add a composite surfactant to the oil phase, wherein the composite surfactant is obtained by mixing sodium dodecylbenzenesulfonate and n-butanol in a mass ratio of 1:1, stirring and dispersing, then adding water, dispersing and homogenizing to obtain a microemulsion, wherein the microemulsion includes 20% oil phase, 30% composite surfactant and the balance water by mass fraction. S3. Add the quaternized cyclodextrin prepared in Preparation Example 1 to acetone, stir and disperse, then add bispyribac-sodium and methylated vegetable oil (model FB-71), and continue stirring to dissolve to obtain an organic phase, wherein the organic phase includes 5% quaternized cyclodextrin, 7% bispyribac-sodium, 0.5% methylated vegetable oil and the balance acetone by mass fraction. S4. The organic phase is poured into the microemulsion and subjected to high-speed shearing, wherein the volume ratio of the organic phase to the microemulsion is 1:7. Then the temperature is raised to 70°C and stirred continuously to volatilize. Finally, the product is obtained by centrifugation, washing and drying.
[0047] Example 6: A compound herbicide containing chlorpyrifos and bispyribac-methyl, differing from Example 1 only in that an equal amount of quaternized cyclodextrin prepared in Preparation Example 2 is used instead of the quaternized cyclodextrin prepared in Preparation Example 1.
[0048] Example 7: A compound herbicide containing chlorpyrifos and bispyribac-methyl, differing from Example 1 only in that an equal amount of quaternized cyclodextrin prepared in Preparation Example 2 is used instead of the quaternized cyclodextrin prepared in Preparation Example 1.
[0049] Comparative Example
[0050] Comparative Example 1, a compound herbicide containing chloropyridinium ester and bispyribac-sodium, differs from Example 1 only in that cyclohexanone is not added in step S1, and the oil phase includes 1.5% chloropyridinium ester by mass, 15% emulsifier and the balance being No. 150 solvent oil.
[0051] Comparative Example 2, a compound herbicide containing chlorpyrifos and bispyribac-methyl, differs from Example 1 only in that an equal amount of octadecylamine polyoxyethylene ether is used to replace the anionic surfactant sodium dodecylbenzenesulfonate.
[0052] Comparative Example 3, a compound herbicide containing chlorpyrifos and bispyribac-sodium, differs from Example 1 only in that the compound surfactant does not include n-butanol, and the compound surfactant is sodium dodecylbenzenesulfonate.
[0053] Comparative Example 4, a compound herbicide containing chlorpyrifos and bispyribac-methyl, differs from Example 1 only in that an equal amount of unmodified β-cyclodextrin is used to replace the quaternized cyclodextrin prepared in Preparation Example 1.
[0054] Comparative Example 5, a compound herbicide containing chlorpyrifos and bispyribac, differs from Example 1 only in that the organic phase does not contain the synergist methylated vegetable oil, and the organic phase includes 5% by mass of quaternized cyclodextrin, 7% by mass of bispyribac, and the balance being acetone.
[0055] Comparative Example 6, a compound herbicide containing chlorpyrifos and bispyribac-sodium, was prepared according to the following method: S1. Add chloropyridinium ester, bispyribac-sodium oxychloride, methylated vegetable oil (model FB-71), cyclohexanone, and an emulsifier obtained by mixing agricultural emulsion No. 500 and agricultural emulsion No. 600 in a mass ratio of 1:1 to solvent oil No. 150. After stirring and dissolving, an oil phase is obtained, wherein the oil phase includes 1.5% chloropyridinium ester, 5% bispyribac-sodium oxychloride, 0.5% methylated vegetable oil, 7% cyclohexanone, 15% emulsifier, and the balance being solvent oil No. 150; S2. Add a composite surfactant to the oil phase, wherein the composite surfactant is obtained by mixing sodium dodecylbenzenesulfonate and n-butanol in a mass ratio of 1:1, stirring and dispersing, then adding water, dispersing and homogenizing to obtain a microemulsion, which is the composite herbicide, wherein the microemulsion includes 20% oil phase, 30% composite surfactant and the balance water by mass fraction.
[0056] Performance testing
[0057] Test sample preparation: The compound herbicides obtained in the examples and comparative examples were added to water to prepare a suspension test sample with a concentration of 3%; Field trial: The soil type of the experimental site was ramie soil, with high fertility, an organic matter content of 2.27%, and a pH value of 6.3. The rice variety used in the trial was "Yangnong Rice No. 1," and the planting method was organic rice transplanting.
[0058] The experimental samples were sprayed with foliar spray when the rice reached the three-leaf stage, with a spray volume of 450 L / hm². 2 The residential area is 66.7 square meters. 2 Intervals were constructed between the small groups. The population size of each hybrid species was investigated, and the control efficacy was calculated using the following method:
[0059] The control area refers to the plot that has not been treated with herbicides; Furthermore, the yield of the plots was measured to characterize the safety of the herbicide.
[0060] The experimental results are shown in Table 1: Table 1 Performance test results
[0061] According to Table 1, combined with Example 1 and Comparative Example 6, it can be seen that Example 1 has high efficacy against different types of weeds, good safety, little impact on crops, and high crop yield. This indicates that the compound herbicide obtained in Example 1 not only has high efficacy against different types of weeds, but also avoids the risk of phytotoxicity from peak concentrations, improves overall safety, and greatly reduces the impact of herbicides on crops.
[0062] Combining Example 1 and Comparative Example 1, it can be seen that the plant control efficacy and yield of Comparative Example 1 are lower than those of Example 1, indicating that the control effect and safety of the compound herbicide in Comparative Example 1 are lower than those in Example 1. The reason is that cyclohexanone was not added to the oil phase of Comparative Example 1, which would affect the solubility of chlorofluoropyridine ester in the oil phase, resulting in abnormal precipitation of chlorofluoropyridine ester during application. The resulting concentration peak would affect the crop and lead to a decrease in safety.
[0063] Based on Examples 1, 2, and 3, it can be seen that the plant control efficacy and yield of Comparative Examples 2 and 3 are lower than those of Example 1. This is because, in Comparative Example 2, a nonionic surfactant was used during the microemulsion formation process. Although a well-formed micelle structure was obtained, the attraction between the quaternized cyclodextrin and the micelle surface was weak during the subsequent coating process, resulting in low coating amount and uneven shell coating. This led to poor structural stability of the compound herbicide, low content of actual active ingredients, and consequently, reduced safety and control efficacy. In Comparative Example 3, no co-surfactant was added, which reduced the structural stability of the micelles in the microemulsion, directly affecting the coating process of the compound herbicide and thus causing a performance decline.
[0064] Combining Example 1 and Comparative Example 4, it can be seen that the control efficacy and yield of Comparative Example 4 are lower than those of Example 1. The reason is that the cyclodextrin in Comparative Example 4 has not undergone quaternization treatment, which also leads to a decrease in coating effect, uneven coating, and a decrease in the content of active ingredients, which in turn leads to a decrease in the weeding efficiency, low stability, and decreased safety of the compound herbicide.
[0065] Combining Example 1 and Comparative Example 5, it can be seen that the control efficacy and yield of Comparative Example 5 are lower than those of Example 1. The reason is that no synergist was added to the organic phase of Comparative Example 5, which reduced the utilization rate of drug molecules in the compound herbicide and the absorption effect of weeds on the active ingredients, thus resulting in a decrease in control efficacy.
[0066] The above-disclosed embodiments are merely a few specific examples of the present invention. However, the embodiments of the present invention are not limited thereto, and any variations that can be conceived by those skilled in the art should fall within the protection scope of the present invention.
Claims
1. A method for preparing a compound herbicide containing chlorpyrifos and bispyribac-methyl, characterized in that, The process includes the following steps: S1. Add chlorofluoropyridine ester, cyclohexanone and emulsifier to solvent oil, stir to dissolve and obtain oil phase; S2. Add a composite surfactant to the oil phase, stir and disperse, then add water and disperse and homogenize to obtain a microemulsion; S3. Add quaternized cyclodextrin to acetone, stir to disperse, then add bispyribac-sodium and synergist, and continue stirring to dissolve to obtain the organic phase; S4. Pour the organic phase into the microemulsion and perform high-speed shearing, then raise the temperature to 65-75℃ and continue stirring to volatilize. Finally, centrifuge, wash and dry to obtain the final product.
2. The method for preparing the compound herbicide containing chlorpyrifos and bispyribac-methyl according to claim 1, characterized in that, The emulsifier includes one or a combination of two of Agricultural Emulsion No. 500 and Agricultural Emulsion No.
600.
3. The method for preparing the compound herbicide containing chlorpyrifos and bispyribac-methyl according to claim 1, characterized in that, The oil phase comprises 1-2% by mass of chlorofluoropyridine ester, 6-9% by mass of cyclohexanone, 10-20% by mass of emulsifier, and the balance being solvent oil.
4. The method for preparing the compound herbicide containing chlorpyrifos and bispyribac-methyl according to claim 1, characterized in that, The composite surfactant comprises an anionic surfactant and a co-surfactant in a mass ratio of 1:(0.5-1); the anionic surfactant comprises one or more of alkylbenzene sulfonic acid surfactants, alkyl sulfate surfactants, and sulfosuccinate surfactants; the co-surfactant comprises one or more of n-butanol, n-pentanol, isoamyl alcohol, n-hexanol, and n-octanol.
5. The method for preparing the compound herbicide containing chlorpyrifos and bispyribac-methyl according to claim 1, characterized in that, The microemulsion comprises 15-20% by mass of an oil phase, 20-30% by mass of a composite surfactant, and the balance being water.
6. The method for preparing the compound herbicide containing chlorpyrifos and bispyribac-methyl according to claim 1, characterized in that, The raw materials for the quaternized cyclodextrin include β-cyclodextrin, epichlorohydrin, and organic amines in a mass ratio of 1:(0.75-0.85):(0.2-0.3); the organic amines include one or more combinations of triethylamine, trimethylamine, tripropylamine, N,N-dimethylethanolamine, and N,N-diethylethanolamine.
7. The method for preparing the compound herbicide containing chlorpyrifos and bispyribac-methyl according to claim 6, characterized in that, The quaternized cyclodextrin was prepared according to the following method: β-Cyclodextrin was dispersed in water, an alkaline solution was added, the temperature was raised to 40-50°C, and the mixture was activated for 10-30 minutes. Then epichlorohydrin was added, and the reaction was continued with stirring for 7-8 hours. Finally, the pretreated cyclodextrin polymer was obtained by filtration, washing, and drying. The pretreated cyclodextrin polymer was swollen with water, and then an organic amine was added. The temperature was raised to 70-80°C, and the mixture was stirred for 6-8 hours. Finally, the product was obtained by filtration, washing, and drying.
8. The method for preparing the compound herbicide containing chlorpyrifos and bispyribac-methyl according to claim 1, characterized in that, The organic phase comprises 2-5% by mass of quaternized cyclodextrin, 5-7% by mass of bispyribac-sodium, 0.5-2% by mass of synergist and the balance being acetone; The synergist includes one or more combinations of methylated vegetable oil and agricultural organosilicon synergist.
9. The method for preparing the compound herbicide containing chlorpyrifos and bispyribac-methyl according to claim 1, characterized in that, The volume ratio of the organic phase to the microemulsion is 1:(6-8).
10. A compound herbicide containing chlorpyrifos and bispyribac-methyl, characterized in that, The compound herbicide containing chlorpyrifos and bispyribac-sodium is prepared according to any one of claims 1 to 9.