Composite water dispersible granules containing emamectin benzoate and preparation process

Abstract

The present invention provides a composite water-dispersible granule containing emamectin benzoate and a preparation process, belonging to the technical field of pesticide preparation; the preparation process comprises the following steps: preparing a modified carrier material; preparing a light-controlled release carrier material; and preparing a composite water-dispersible granule. The present invention uses bentonite as a raw material to prepare a light-controlled release carrier material, and when the carrier material is used to load the original drug component of the insecticide, the original drug molecules of the insecticide can be slowly released from the pores and surface of the bentonite, thereby achieving effective control of the release rate of the insecticide, prolonging the action time of the agent, and reducing the number of times of application. In addition, after methyl cinnamate is grafted on the surface of the modified carrier material to prepare a light-controlled release carrier material, and the original drug of the insecticide is loaded, the release rate of the original drug of the insecticide is reduced under strong light irradiation, thereby avoiding light degradation after the release of the insecticide solution and reducing the efficacy.

Description

Technical Field

[0001] The invention relates to the technical field of pesticide preparation, and in particular to a composite water-dispersible granule containing emamectin benzoate and a preparation process. Background Art

[0002] Emamectin benzoate (full name: emamectin benzoate) is a highly effective, broad-spectrum and low-toxic bio-based insecticide that occupies an important position in the field of agricultural pest control. It has excellent killing effects on a variety of pests, such as lepidopteran pests and coleopteran pests, and can effectively ensure the growth and yield of crops and reduce economic losses caused by pest damage.

[0003] With the intensification and modernization of agricultural production, the requirements for pesticide formulations are becoming increasingly stringent. Traditional pesticide formulations, such as emulsifiable concentrates and wettable powders, have gradually exposed many limitations; emulsifiable concentrate formulations contain a large amount of organic solvents, which are not only expensive, but also pose safety hazards during production, transportation, storage and use, and are prone to environmental pollution and excessive residues in agricultural products; wettable powders have defects such as dust flying, difficulty in uniform dispersion, and unstable efficacy, which affect the effect of application and ease of operation. As a new type of environmentally friendly pesticide formulation, water-dispersible granules have emerged and attracted much attention. They have many significant advantages: first, there is no dust flying, which significantly reduces the risk of pollution to the environment and the applicators, and is conducive to protecting the health of the applicators and the safety of the surrounding ecological environment; second, good dispersibility and suspension, can quickly disperse in water to form a uniform and stable suspension, ensure that the active ingredients of the pesticide are evenly distributed in the application area, and improve the consistency and reliability of the efficacy; third, high storage stability, not easy to agglomerate and deteriorate due to moisture, convenient for long-term storage and transportation; fourth, good compatibility with a variety of pesticide active ingredients, convenient for compounding and developing multifunctional and efficient compound pesticide preparations to meet the complex and changeable needs of agricultural pest control. However, after the existing water-dispersible granule insecticides are prepared into liquid and sprayed, when exposed to strong light, most of the original drug ingredients such as emamectin benzoate are easily degraded by photochemical reactions, resulting in reduced biological activity, thereby reducing the insecticidal efficacy of the water-dispersible granule insecticide.

[0004] Therefore, it is necessary to propose a composite water dispersible granule containing emamectin benzoate and a preparation process that can avoid degradation of the original drug components, so as to improve its insecticidal efficiency. Summary of the invention

[0005] In view of the shortcomings of the prior art, the object of the present invention is to provide a composite water-dispersible granule containing emamectin benzoate and a preparation process.

[0006] A preparation process of composite water dispersible granules containing emamectin benzoate comprises the following steps:

[0007] S1: Preparation of modified support materials

[0008] The bentonite is prepared into a bentonite dispersion for standby use, and then ammonia water, deionized water and tetraethyl orthosilicate are stirred and mixed, and the bentonite dispersion is added, and stirred to react to prepare a primary coated bentonite, and then added together with citric acid into deionized water to carry out a hydrothermal reaction to prepare a secondary coated bentonite, and finally added into a sodium hydroxide solution to react to obtain a modified carrier material;

[0009] S2: Preparation of light-controlled release carrier materials

[0010] The modified carrier material is dispersed in anhydrous ethanol, a silane coupling agent is added for surface functionalization, and then dispersed in toluene, methyl cinnamate and triethylamine are added for reaction to obtain a light-controlled release carrier material;

[0011] S3: Preparation of composite water dispersible granules

[0012] Emamectin benzoate, rotenone and celangulin are dissolved in anhydrous ethanol, and then the above-mentioned light-controlled release carrier material is added for loading to prepare a drug-loaded material, which is then mixed with a dispersant, a wetting agent, a disintegrant and an aqueous binder solution to form a composite water-dispersible granule.

[0013] Furthermore, S1 specifically includes the following steps:

[0014] S1.1: Grind and sieve the bentonite, add it into deionized water at a solid-liquid ratio of 1g:(80-90)mL, and disperse it ultrasonically for 20-30min to obtain a bentonite dispersion;

[0015] S1.2: Add ammonia water to deionized water in a volume ratio of 1: (20-30) to prepare an ammonia solution, then add tetraethyl orthosilicate while stirring, and then add it to the above bentonite dispersion, continue stirring for 1-2 hours, heat at 50-60°C and let stand for 8-10 hours, centrifuge, wash and dry to obtain a primary coated bentonite;

[0016] S1.3: Add citric acid and the primary coated bentonite into deionized water at a solid-liquid ratio of (3-5) g: 1 g: (50-60) mL, stir and disperse thoroughly, transfer to a high-pressure reactor, heat at 135-145°C for 4-6 hours, cool, separate ions, wash and dry to obtain secondary coated bentonite;

[0017] S1.4: The secondary coated bentonite is immersed in a sodium hydroxide solution with a concentration of 1 mol / L, heated and stirred at 60-70°C for 2-3 hours, the silicon dioxide layer is removed, and the modified carrier material is obtained by centrifugal separation, washing and drying.

[0018] Furthermore, S2 specifically includes the following steps:

[0019] S2.1: Add the modified carrier material obtained in step S1.4 to anhydrous ethanol at a solid-liquid ratio of 1 g: (65-75) mL, stir and disperse thoroughly, then add a silane coupling agent, continue stirring for 20-24 hours, centrifuge, wash and dry to obtain a surface functionalized carrier;

[0020] S2.2: Add the above-mentioned surface functionalized carrier into toluene at a solid-liquid ratio of 1g: (45-55)mL, stir and disperse thoroughly, then add methyl cinnamate and triethylamine, and heat under reflux at 90-100°C for 6-8h under a nitrogen atmosphere. After cooling, centrifuge, wash and dry to obtain a light-controlled release carrier material.

[0021] Furthermore, S3 specifically includes the following steps:

[0022] S3.1: Dissolve emamectin benzoate, rotenone and celangulin in anhydrous ethanol at a solid-liquid ratio of (6-8) g: (1-2) g: 1 g: (400-500) mL, then add the light-controlled release carrier material prepared in step S2.2 at a solid-liquid ratio of 1 g: (50-60) mL, stir for 1-2 h, and then ultrasonically load for 2-3 h, centrifuge at 9000-10000 r / min for 10-20 min, filter and dry to obtain the drug-loaded material;

[0023] S3.2: Add the above-mentioned drug-carrying materials, dispersant, wetting agent and disintegrant into a vacuum mixer, mix them thoroughly and evenly to obtain a dry blend;

[0024] S3.3: Adding the binder aqueous solution to the above dry mixture while stirring, and then placing it in an extruder for extrusion granulation, and after drying and sieving, obtaining a composite water-dispersible granule.

[0025] Furthermore, the volume ratio of tetraethyl orthosilicate to ammonia water is 1:(1-2), and the volume ratio of bentonite dispersion to ammonia solution is (1.8-2.2):1.

[0026] Furthermore, the silane coupling agent is 3-aminopropyltriethoxysilane, and the volume ratio of the silane coupling agent to anhydrous ethanol is 1: (40-50) mL.

[0027] Furthermore, the amount of methyl cinnamate added is 2-3 times the mass of the surface functionalized carrier, and the volume ratio of triethylamine to toluene is 1:(90-100).

[0028] Furthermore, the weight percentage of each component in the composite water-dispersible granules is: 4-6% dispersant, 2-3% wetting agent, 15-20% disintegrant, 2-4% binder, and the balance is drug-carrying material; wherein the dispersant is one or more of lignin sulfonate, polycarboxylate and naphthalene sulfonate; the wetting agent is one or more of sodium dodecylbenzene sulfonate or sodium dodecyl sulfate; the disintegrant is one or more of sodium sulfate, calcium sulfate, sodium bicarbonate, magnesium chloride and sodium chloride; the binder is one or more of starch, carboxymethyl cellulose, gelatin and carboxyethyl cellulose.

[0029] Furthermore, a composite water dispersible granule containing emamectin benzoate is prepared by any of the above-mentioned preparation processes for a composite water dispersible granule containing emamectin benzoate.

[0030] Compared with the prior art, the present invention has at least the following beneficial effects:

[0031] 1. The present invention uses bentonite as a raw material to prepare a light-controlled release carrier material, and when the carrier material is used to load the original pesticide component, the original pesticide molecules can be slowly released from the pores and surface of the bentonite, thereby achieving effective control of the release rate of the pesticide, extending the action time of the agent, and reducing the number of applications.

[0032] 2. The present invention adds bentonite to a mixed solution of ammonia water, tetraethyl orthosilicate and deionized water to carry out a hydrolysis reaction, so that the surface of the bentonite is coated with a silicon dioxide layer to obtain a primary coated bentonite. The primary coated bentonite and citric acid are then added to deionized water for a high-pressure hydrothermal reaction, so that the surface of the silicon dioxide layer of the bentonite is further coated with a carbon layer. Finally, the silicon dioxide layer is removed by a sodium hydroxide solution reaction to prepare a modified carrier material. Since the coating of the silicon dioxide and carbon layers significantly increases the specific surface area of ​​the carrier material, more adsorption sites can be provided. At the same time, the porous structure formed after the silicon dioxide layer is removed is conducive to the diffusion and loading of the pesticide original drug molecules. Therefore, the loading rate of the modified carrier material on the pesticide original drug can be effectively improved, thereby improving the insecticidal effect and action time of the prepared composite water-dispersible granules.

[0033] 3. The present invention first uses 3-aminopropyltriethoxysilane to functionalize the surface of the modified carrier material, then disperses it in toluene, adds methyl cinnamate, and reacts under the catalysis of triethylamine to graft methyl cinnamate on the surface of the modified carrier material. Since methyl cinnamate has photosensitivity, when irradiated by ultraviolet rays or strong light, dimerization occurs to form a cross-linked structure, making the polymer chain tighter. In the dark or when irradiated by weak light, the cross-linked structure breaks and the polymer chain returns to a loose state. Therefore, after methyl cinnamate is grafted on the surface of the modified carrier material to prepare a light-controlled release carrier material and loaded with the original insecticide, the release rate of the original insecticide is reduced under strong light irradiation, thereby reducing the amount of light degradation of the insecticide solution after release, thereby ensuring the efficacy.

[0034] 4. When the present invention uses a light-controlled release carrier material to simultaneously load emamectin benzoate, rotenone and celangulin to prepare a composite water-dispersible granule, since emamectin benzoate focuses on interfering with the transmission of neural signals, rotenone mainly destroys the energy metabolism of insects, and celangulin has both effects on the nervous system and multiple functions such as antifeedant and stomach poison. When the three are used in combination, they can attack the physiological functions of insects from multiple angles, making it difficult for insects to resist the effects of insecticides through their own physiological adjustments, which helps to further improve the insecticidal effect of the composite water-dispersible granules. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings, which are incorporated herein and constitute a part of the specification, illustrate embodiments of the present disclosure and, together with the description, further serve to explain the principles of the present disclosure and to enable those skilled in the relevant art to make and use the present disclosure.

[0036] Figure 1 The present invention is a flow chart of the preparation process of the composite water dispersible granules containing emamectin benzoate used in the embodiments of the present invention.

[0037] Figure 2 The cumulative release rate curve of the composite water dispersible granules prepared in Example 1 of the present invention under dark and UV light irradiation environments.

[0038] Figure 3 This is a cumulative release rate curve of the composite water dispersible granules prepared in Comparative Example 2 of the present invention under dark and UV light irradiation environments. DETAILED DESCRIPTION

[0039] The composite water dispersible granules containing emamectin benzoate and the preparation process provided by the present invention are described in detail below with reference to the accompanying drawings and specific embodiments.

[0040] Example 1

[0041] A preparation process of composite water dispersible granules containing emamectin benzoate, such as Figure 1 As shown, the following steps are included:

[0042] S1: Preparation of modified support materials

[0043] S1.1: Grind and sieve bentonite, add it into deionized water at a solid-liquid ratio of 1g:80mL, and disperse it ultrasonically for 20min to obtain a bentonite dispersion;

[0044] S1.2: Add ammonia water to deionized water at a volume ratio of 1:20 to prepare an ammonia solution, then add tetraethyl orthosilicate while stirring, and then add it to the above bentonite dispersion, continue stirring for 1 hour, heat at 50°C and stand for 8 hours, centrifuge, wash and dry to obtain a primary coated bentonite, wherein the volume ratio of tetraethyl orthosilicate to ammonia water is 1:1, and the volume ratio of bentonite dispersion to ammonia solution is 1.8:1;

[0045] S1.3: Add citric acid and the primary coated bentonite into deionized water at a solid-liquid ratio of 3g:1g:50mL, stir and disperse thoroughly, transfer to a high-pressure reactor, heat at 135°C for 4h, cool, separate ions, wash and dry to obtain secondary coated bentonite;

[0046] S1.4: immerse the secondary coated bentonite in a sodium hydroxide solution with a concentration of 1 mol / L, heat and stir at 60°C for 2 h, remove the silicon dioxide layer, centrifuge, wash and dry to obtain a modified carrier material;

[0047] S2: Preparation of light-controlled release carrier materials

[0048] S2.1: Add the modified carrier material obtained in step S1.4 to anhydrous ethanol at a solid-liquid ratio of 1 g:65 mL, stir and disperse thoroughly, then add 3-aminopropyltriethoxysilane, continue stirring for 20 hours, centrifuge, wash and dry to obtain a surface functionalized carrier, wherein the volume ratio of silane coupling agent to anhydrous ethanol is 1:40;

[0049] S2.2: Add the surface functionalized carrier to toluene at a solid-liquid ratio of 1g:45mL, stir and disperse thoroughly, then add methyl cinnamate and triethylamine, and heat under reflux at 90°C for 6h in a nitrogen atmosphere. After cooling, centrifuge, wash and dry to obtain a light-controlled release carrier material, wherein the amount of methyl cinnamate added is twice the mass of the surface functionalized carrier, and the volume ratio of triethylamine to toluene is 1:90;

[0050] S3: Preparation of composite water dispersible granules

[0051] S3.1: Dissolve emamectin benzoate, rotenone and celangulin in anhydrous ethanol at a solid-liquid ratio of 6g:1g:1g:400mL, then add the light-controlled release carrier material prepared in step S2.2 at a solid-liquid ratio of 1g:50mL, stir for 1h, and then ultrasonically load for 2h, centrifuge at 9000r / min for 10min, filter and dry to obtain the drug-loaded material;

[0052] S3.2: Add 77% of the above drug-loaded material, 4% of lignin sulfonate, 2% of sodium dodecylbenzene sulfonate and 15% of sodium sulfate into a vacuum mixer, mix thoroughly and evenly to obtain a dry blend;

[0053] S3.3: Add 2% starch and water to the above dry mixture while stirring to make a wet material, then put it into an extruder for extrusion granulation, and after drying and sieving, obtain a composite water-dispersible granule.

[0054] Example 2

[0055] A preparation process of composite water dispersible granules containing emamectin benzoate, such as Figure 1 As shown, the following steps are included:

[0056] S1: Preparation of modified support materials

[0057] S1.1: Grind and sieve bentonite, add it into deionized water at a solid-liquid ratio of 1g:85mL, and disperse it ultrasonically for 25min to obtain a bentonite dispersion;

[0058] S1.2: Ammonia water is added to deionized water at a volume ratio of 1:25 to prepare an ammonia solution, and then tetraethyl orthosilicate is added while stirring, and then added to the above bentonite dispersion, and stirring is continued for 1.5 hours, and then heated at 55°C and allowed to stand for 9 hours, and then centrifuged, washed and dried to obtain a primary coated bentonite, wherein the volume ratio of tetraethyl orthosilicate to ammonia water is 1:1.5, and the volume ratio of bentonite dispersion to ammonia solution is 2:1;

[0059] S1.3: Add citric acid and the primary coated bentonite into deionized water at a solid-liquid ratio of 4g:1g:55mL, stir and disperse thoroughly, transfer to a high-pressure reactor, heat at 140°C for 5h, cool, separate ions, wash and dry to obtain secondary coated bentonite;

[0060] S1.4: The secondary coated bentonite is immersed in a sodium hydroxide solution with a concentration of 1 mol / L, heated and stirred at 65°C for 2.5 hours, the silicon dioxide layer is removed, and the modified carrier material is obtained by centrifugal separation, washing and drying;

[0061] S2: Preparation of light-controlled release carrier materials

[0062] S2.1: Add the modified carrier material obtained in step S1.4 to anhydrous ethanol at a solid-liquid ratio of 1 g:70 mL, stir and disperse thoroughly, then add 3-aminopropyltriethoxysilane, continue stirring for 22 hours, centrifuge, wash and dry to obtain a surface functionalized carrier, wherein the volume ratio of silane coupling agent to anhydrous ethanol is 1:45;

[0063] S2.2: Add the surface functionalized carrier to toluene at a solid-liquid ratio of 1g:50mL, stir and disperse thoroughly, then add methyl cinnamate and triethylamine, and heat under reflux at 95°C for 7h in a nitrogen atmosphere. After cooling, centrifuge, wash and dry to obtain a light-controlled release carrier material, wherein the amount of methyl cinnamate added is twice the mass of the surface functionalized carrier, and the volume ratio of triethylamine to toluene is 1:95;

[0064] S3: Preparation of composite water dispersible granules

[0065] S3.1: Dissolve emamectin benzoate, rotenone and celangulin in anhydrous ethanol at a solid-liquid ratio of 7g:1.5g:1g:450mL, then add the light-controlled release carrier material prepared in step S2.2 at a solid-liquid ratio of 1g:55mL, stir for 1.5h, and then ultrasonically load for 2.5h, centrifuge at 9500r / min for 15min, filter and dry to obtain the drug-loaded material;

[0066] S3.2: Add 72% of the above drug-loaded material, 5% of polycarboxylate, 2.5% of sodium dodecylbenzene sulfonate and 17.5% of calcium sulfate into a vacuum mixer, mix thoroughly and evenly to obtain a dry blend;

[0067] S3.3: Add 3% carboxymethyl cellulose and water to the above dry mixture while stirring to make a wet material, which is then placed in an extruder for extrusion granulation. After drying and sieving, composite water-dispersible granules are obtained.

[0068] Example 3

[0069] A preparation process of composite water dispersible granules containing emamectin benzoate, such as Figure 1 As shown, the following steps are included:

[0070] S1: Preparation of modified support materials

[0071] S1.1: Grind and sieve bentonite, add it into deionized water at a solid-liquid ratio of 1g:90mL, and disperse it ultrasonically for 30 minutes to obtain a bentonite dispersion;

[0072] S1.2: Add ammonia water to deionized water at a volume ratio of 1:30 to prepare an ammonia solution, then add tetraethyl orthosilicate while stirring, and then add it to the above bentonite dispersion, continue stirring for 2 hours, heat at 60°C and stand for 10 hours, centrifuge, wash and dry to obtain a primary coated bentonite, wherein the volume ratio of tetraethyl orthosilicate to ammonia water is 1:2, and the volume ratio of bentonite dispersion to ammonia solution is 2.2:1;

[0073] S1.3: Add citric acid and the primary coated bentonite into deionized water at a solid-liquid ratio of 5g:1g:60mL, stir and disperse thoroughly, transfer to a high-pressure reactor, heat at 145°C for 6h, cool, separate ions, wash and dry to obtain secondary coated bentonite;

[0074] S1.4: The secondary coated bentonite is immersed in a sodium hydroxide solution with a concentration of 1 mol / L, heated and stirred at 70°C for 3 h, the silicon dioxide layer is removed, and the modified carrier material is obtained by centrifugal separation, washing and drying;

[0075] S2: Preparation of light-controlled release carrier materials

[0076] S2.1: Add the modified carrier material obtained in step S1.4 to anhydrous ethanol at a solid-liquid ratio of 1 g:75 mL, stir and disperse thoroughly, then add 3-aminopropyltriethoxysilane, continue stirring for 24 hours, centrifuge, wash and dry to obtain a surface functionalized carrier, wherein the volume ratio of silane coupling agent to anhydrous ethanol is 1:50;

[0077] S2.2: The surface functionalized carrier is added to toluene at a solid-liquid ratio of 1g:55mL, and after sufficient stirring and dispersion, methyl cinnamate and triethylamine are added, and the mixture is heated to reflux at 100°C for 8h under a nitrogen atmosphere. After cooling, the mixture is centrifuged, washed and dried to obtain a light-controlled release carrier material, wherein the amount of methyl cinnamate added is 3 times the mass of the surface functionalized carrier, and the volume ratio of triethylamine to toluene is 1:100;

[0078] S3: Preparation of composite water dispersible granules

[0079] S3.1: Dissolve emamectin benzoate, rotenone and celangulin in anhydrous ethanol at a solid-liquid ratio of 8g:2g:1g:500mL, then add the light-controlled release carrier material prepared in step S2.2 at a solid-liquid ratio of 1g:60mL, stir for 2h, and then ultrasonically load for 3h, centrifuge at 10000r / min for 20min, filter and dry to obtain the drug-loaded material;

[0080] S3.2: Add 67% of the above drug-loaded material, 6% of naphthalenesulfonate, 3% of sodium dodecyl sulfate and 20% of sodium bicarbonate into a vacuum mixer, mix thoroughly and evenly to obtain a dry blend;

[0081] S3.3: Add 4% gelatin and water to the above dry mixture while stirring to make a wet material, which is then placed in an extruder for extrusion granulation. After drying and sieving, composite water-dispersible granules are obtained.

[0082] Comparative Example 1

[0083] The difference between this comparative example 1 and example 1 is that step S1 is removed, and the modified carrier material in step S2.1 is replaced by an equal amount of bentonite.

[0084] Comparative Example 2

[0085] The difference between Comparative Example 2 and Example 1 is that step S2 is removed, and the light-controlled release carrier material in step S3.1 is replaced by an equal amount of modified carrier material.

[0086] Comparative Example 3

[0087] The difference between Comparative Example 3 and Example 1 is that rotenone and celangulin in step S3.1 are replaced by an equal amount of emamectin benzoate.

[0088] Comparative Example 4

[0089] The difference between this comparative example 4 and example 1 is that the emamectin benzoate and celangulin in step S3.1 are replaced by an equal amount of rotenone.

[0090] Comparative Example 5

[0091] The difference between this comparative example 5 and example 1 is that the emamectin benzoate and rotenone in step S3.1 are replaced by an equal amount of celangulin.

[0092] Test Case

[0093] Test 1: The mass concentrations of emamectin benzoate, rotenone and celangulin in the filtrate obtained by ultrasonic loading of emamectin benzoate, rotenone and celangulin with a carrier and centrifugal separation in Examples 1-3 and Comparative Example 1 were detected by high performance liquid chromatography. Emamectin benzoate, rotenone and celangulin were collectively referred to as technical drugs, and the loading rate was calculated according to the following formula:

[0094] Loading rate (%) = [(initial mass of original drug - mass concentration of original drug in filtrate × volume of filtrate) / initial mass of original drug] × 100%. The results are shown in Table 1.

[0095] Table 1: Comparison of loading rates of emamectin benzoate, rotenone and celangulin

[0096]

[0097] As can be seen from Table 1, in Comparative Example 1, after the bentonite is not coated and modified, the loading rate of the obtained carrier material for the original drug is about 54.7%, which is much lower than that in Example 1. It can be seen that by adding bentonite to a mixed solution of ammonia water, tetraethyl orthosilicate and deionized water, a hydrolysis reaction is carried out to coat the surface of the bentonite with a silicon dioxide layer, and then adding it together with citric acid into deionized water to carry out a high-pressure hydrothermal reaction, so that the surface of the silicon dioxide layer of the bentonite is further coated with a carbon layer, and finally the silicon dioxide layer is removed by reaction with a sodium hydroxide solution to prepare a modified carrier material, the loading rate of the bentonite for the original drug can be effectively improved.

[0098] Test 2: In order to increase the solubility of emamectin benzoate, rotenone and celangulin, a mixed solution of anhydrous ethanol: deionized water = 3:1 (v / v) was selected as the release medium. 10 mg of the composite water-dispersible granules prepared in Example 1 and Comparative Example 2 were weighed respectively and placed in a 50 mL conical flask of the release medium to simulate their release behavior under UV light and darkness at 25°C. 3 mL of the release medium was removed at 2h, 4h, 6h, 8h, 10h, 12h, 24h, 36h, 48h, 60h, and 72h, respectively, the absorbance was detected, and 3 mL of blank release medium was added, and then the cumulative release rate curves under UV light and darkness were calculated and plotted, as shown in FIG. Figure 2 and Figure 3 shown.

[0099] Depend on Figure 2 and Figure 3 It can be seen that the cumulative release rate of the composite water-dispersible granules prepared in Example 1 in the dark for 72 hours is about 90.8%, and the cumulative release rate in the UV light irradiation environment for 72 hours is about 57.3%. It can be seen that the light-controlled release carrier material prepared by the present invention has a sustained release effect, and the cumulative release rates of emamectin benzoate, rotenone and celangulin in the light environment are much lower than those in the dark environment. In Comparative Example 2, when methyl cinnamate with photosensitivity is not grafted on the surface of the modified carrier material, the cumulative release rates of the composite water-dispersible granules prepared in the dark environment and under the UV light environment are both about 91%. It can be seen that by grafting methyl cinnamate with photosensitivity on the surface of the modified carrier material, the release rate of the original insecticide under strong light irradiation can be effectively reduced, thereby avoiding the degradation of the original insecticide by light and reducing the efficacy.

[0100] Test 3: Field efficacy test on cabbage diamondback moth

[0101] The diamondback moth was used as the control target, and the experimental field was 80m 2 , were randomly divided into 4 groups, namely, Example 1, Comparative Example 3, Comparative Example 4 and Comparative Example 5, each with 20 m 2Each group sprayed drugs from the peak of egg hatching to the best control period of 1st and 2nd instar larvae to control Plutella xylostella, and counted the number of larvae of each instar before spraying as the insect population base, and counted the number of remaining live insects on the first and third days after spraying to calculate the mortality rate. The results are shown in Table 2.

[0102] Statistical counting method: adopt the 5-point sampling method, calculate the average value of the insect population of the 5 sampling points, and count the insect population base of each group;

[0103] Application situation:

[0104] Example 1 group: spray the composite water dispersible granules prepared in Example 1, the dosage per mu is 15g / mu, and the spray is diluted with 30kg / mu of water;

[0105] Comparative Example 3 group: spray the composite water dispersible granules prepared in Comparative Example 3, the dosage per mu is 15g / mu, and the spray is diluted with 30kg / mu of water;

[0106] Comparative Example 4 group: spray the composite water dispersible granules prepared in Comparative Example 4, the dosage per mu is 15g / mu, and the spray is diluted with 30kg / mu of water;

[0107] Comparative Example 5 group: spray the composite water-dispersible granules prepared in Comparative Example 5, the dosage per mu is 15g / mu, and the spray is diluted with 30kg / mu of water.

[0108] Table 2: Comparison of efficacy test results of composite water dispersible granules

[0109]

[0110] As can be seen from Table 2, the composite water-dispersible granules prepared by using single emamectin benzoate, rotenone and celangulin in Comparative Examples 3, 4 and 5 had lower mortality rates of Plutella xylostella on the 1st and 3rd days after spraying than those in Example 1. This shows that the combined use of emamectin benzoate, rotenone and celangulin can further increase the mortality rate of Plutella xylostella, that is, emamectin benzoate, rotenone and celangulin have a synergistic insecticidal effect.

[0111] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A process for preparing a composite water dispersible granule containing emamectin benzoate, characterized in that: The steps include: S1: Preparation of modified support materials The bentonite is prepared into a bentonite dispersion for later use, and then ammonia water is mixed with deionized water to prepare an ammonia solution, and the solution is mixed with tetraethyl orthosilicate, and then the bentonite dispersion is added, and the solution is stirred to react to prepare a primary coated bentonite, and then citric acid and the primary coated bentonite are added into deionized water at a solid-liquid ratio of (3-5) g:1 g:(50-60) mL to carry out a hydrothermal reaction to prepare a secondary coated bentonite, and finally a sodium hydroxide solution is added to react to obtain a modified carrier material; The volume ratio of tetraethyl orthosilicate to ammonia water is 1:(1-2), and the volume ratio of bentonite dispersion to ammonia solution is (1.8-2.2):1; S2: Preparation of light-controlled release carrier materials The modified carrier material is dispersed in anhydrous ethanol, and a silane coupling agent is added for surface functionalization to obtain a surface functionalized carrier, and then the modified carrier is dispersed in toluene, and methyl cinnamate and triethylamine are added for reaction to obtain a light-controlled release carrier material; Wherein, the silane coupling agent is 3-aminopropyltriethoxysilane, and the volume ratio of the silane coupling agent to anhydrous ethanol is 1: (40-50); The amount of methyl cinnamate added is 2-3 times the mass of the surface functionalized carrier, and the volume ratio of triethylamine to toluene is 1:(90-100); S3: Preparation of composite water dispersible granules Emamectin benzoate, rotenone and celangulin are dissolved in anhydrous ethanol, and then the above-mentioned light-controlled release carrier material is added for loading to prepare a drug-loaded material, which is then mixed with a dispersant, a wetting agent, a disintegrant and an aqueous binder solution to form a composite water-dispersible granule.

2. The preparation process of a composite water dispersible granule containing emamectin benzoate according to claim 1, characterized in that: S1 includes the following steps: S1.1: Grind and sieve the bentonite, add it into deionized water at a solid-liquid ratio of 1g:(80-90)mL, and ultrasonically disperse it for 20-30min to obtain a bentonite dispersion; S1.2: Add ammonia water to deionized water in a volume ratio of 1: (20-30) to prepare an ammonia solution, then add tetraethyl orthosilicate while stirring, and then add it to the above bentonite dispersion, continue stirring for 1-2 hours, heat at 50-60°C and let stand for 8-10 hours, centrifuge, wash and dry to obtain a primary coated bentonite; S1.3: Add citric acid and the primary coated bentonite into deionized water at a solid-liquid ratio of (3-5) g: 1 g: (50-60) mL, stir and disperse thoroughly, transfer to a high-pressure reactor, heat at 135-145°C for 4-6 hours, cool, separate ions, wash and dry to obtain secondary coated bentonite; S1.4: The secondary coated bentonite is immersed in a sodium hydroxide solution with a concentration of 1 mol / L, heated and stirred at 60-70°C for 2-3 hours, the silicon dioxide layer is removed, and the modified carrier material is obtained by centrifugal separation, washing and drying.

3. A process for preparing a composite water dispersible granule containing emamectin benzoate according to claim 2, characterized in that: S2 includes the following steps: S2.1: Add the modified carrier material obtained in step S1.4 to anhydrous ethanol at a solid-liquid ratio of 1 g: (65-75) mL, stir and disperse thoroughly, then add a silane coupling agent, continue stirring for 20-24 hours, centrifuge, wash and dry to obtain a surface functionalized carrier; S2.2: Add the above-mentioned surface functionalized carrier into toluene at a solid-liquid ratio of 1g: (45-55)mL, stir and disperse thoroughly, then add methyl cinnamate and triethylamine, and heat under reflux at 90-100°C for 6-8h under a nitrogen atmosphere. After cooling, centrifuge, wash and dry to obtain a light-controlled release carrier material.

4. The preparation process of a composite water dispersible granule containing emamectin benzoate according to claim 3, characterized in that: S3 includes the following steps: S3.1: Dissolve emamectin benzoate, rotenone and celangulin in anhydrous ethanol at a solid-liquid ratio of (6-8) g: (1-2) g: 1 g: (400-500) mL, then add the light-controlled release carrier material prepared in step S2.2 at a solid-liquid ratio of 1 g: (50-60) mL, stir for 1-2 h, and then ultrasonically load for 2-3 h, centrifuge at 9000-10000 r / min for 10-20 min, filter and dry to obtain the drug-loaded material; S3.2: Add the above-mentioned drug-carrying materials, dispersant, wetting agent and disintegrant into a vacuum mixer, mix them thoroughly and evenly to obtain a dry blend; S3.3: Adding the binder aqueous solution to the above dry mixture while stirring, and then placing it in an extruder for extrusion granulation, and after drying and sieving, obtaining a composite water-dispersible granule.

5. The preparation process of a composite water dispersible granule containing emamectin benzoate according to claim 4, characterized in that: The weight percentage of each component in the composite water-dispersible granules is: 4-6% dispersant, 2-3% wetting agent, 15-20% disintegrant, 2-4% binder, and the balance is drug-carrying material; wherein the dispersant is one or more of lignin sulfonate, polycarboxylate and naphthalene sulfonate; the wetting agent is one or more of sodium dodecylbenzene sulfonate or sodium dodecyl sulfate; the disintegrant is one or more of sodium sulfate, calcium sulfate, sodium bicarbonate, magnesium chloride and sodium chloride; the binder is one or more of starch, carboxymethyl cellulose, gelatin and carboxyethyl cellulose.

6. A composite water dispersible granule containing emamectin benzoate, characterized in that: The emamectin benzoate-containing composite water dispersible granules are prepared by the preparation process of any one of claims 1 to 5.

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