Mancozeb wettable powder and preparation method thereof

Abstract

The invention relates to the technical field of pesticide preparations, and provides mancozeb wettable powder and a preparation method thereof. The mancozeb wettable powder is prepared from the following raw materials in parts by weight: 82 to 85 parts of mancozeb, 7 to 10 parts of attapulgite-diatomite-nano aluminum oxide composite filler, 5 to 6 parts of dispersing agent, 1 to 2 parts of wetting agent and 0.5 to 1 part of stabilizing agent. According to the mancozeb wettable powder and the preparation method thereof provided by the invention, the adhesiveness of the mancozeb raw medicine is improved, the medicine loss caused by high temperature or low temperature is reduced, and the persistence of the medicine effect is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of pesticide preparations, and in particular to a mancozeb wettable powder and a preparation method thereof. Background Art

[0002] Mancozeb, also known as Dasheng M-45 and Penke, is a highly effective, low-toxic, broad-spectrum protective fungicide. Its technical form is a grayish-yellow powder that is insoluble in water and poorly soluble in common organic solvents. It decomposes and becomes ineffective in the presence of acids or alkalis. Mancozeb primarily kills bacteria through the action of metal ions, resulting in high efficacy, low toxicity, and resistance to bacterial resistance. It also has therapeutic effects on manganese and zinc deficiencies in crops.

[0003] Mancozeb is highly effective against downy mildew on various crops, as well as early blight, late blight, leaf spot, and blight on solanaceous vegetables. It is a broad-spectrum fungicide that effectively protects against a wide range of pathogens. It is primarily used to control downy mildew, anthracnose, and brown spot on vegetables, and is currently an ideal agent for controlling early blight of tomatoes and late blight of potatoes. Furthermore, mancozeb can effectively control diseases resistant to carbendazim. However, in practice, existing mancozeb suffers from reduced efficacy during storage, which compromises disease control. Based on this, the present invention provides a mancozeb wettable powder and a method for its preparation. Summary of the Invention

[0004] The present invention provides a mancozeb wettable powder and a preparation method thereof, which improves the adhesion of the mancozeb technical, reduces the loss of the drug caused by high or low temperatures, and improves the sustainability of the drug effect.

[0005] The technical solutions of the present invention are as follows: In a first aspect, the present invention provides a mancozeb wettable powder comprising the following materials in parts by weight: 82-85 parts of mancozeb, 7-10 parts of attapulgite-diatomaceous earth-nanoalumina composite filler, 5-6 parts of a dispersant, 1-2 parts of a wetting agent, and 0.5-1 part of a stabilizer.

[0006] As a further technical solution, the preparation method of the attapulgite-diatomite-nanoalumina composite filler includes: mixing attapulgite and diatomite, calcining them, and then immersing them in a hydrochloric acid solution to prepare a attapulgite-diatomite composite substrate; adding the attapulgite-diatomite composite substrate to the Al(OH)3 sol, stirring and mixing at 55-65°C for 2-3h, and calcining at 500-550°C for 1-1.5h to obtain a substrate loaded with alumina, which is then dispersed in ethanol, and a silane coupling agent is added, stirred, and centrifuged to obtain the substrate.

[0007] As a further technical solution, the preparation method of the attapulgite-diatomite composite substrate includes: mixing attapulgite and diatomite in a weight ratio of 4-5:1, heating to 580-600°C at 4-6°C / min and calcining for 2-3h, immersing the calcined product in a hydrochloric acid aqueous solution with a mass fraction of 10%-12%, stirring at 70-80°C for 2-3h, filtering and washing with deionized water to neutrality, and drying at 60-70°C to constant weight to obtain a attapulgite-diatomite composite substrate; the weight ratio of the calcined product to the hydrochloric acid aqueous solution is 1:3-4.

[0008] As a further technical solution, the preparation method of the Al(OH)3 sol includes: mixing aluminum isopropoxide and ethanol in a mass ratio of 1:10-12, adding nitric acid to adjust the pH to 4-5, and hydrolyzing at 80-90°C for 3-4h to obtain the obtained product.

[0009] As a further technical solution, the aluminum isopropoxide is 5%-10% of the total mass of attapulgite and diatomaceous earth.

[0010] As a further technical solution, the silane coupling agent is KH550; the weight ratio of the alumina-loaded substrate, ethanol and silane coupling agent is 1:5-6:0.05-0.1.

[0011] As a further technical solution, the temperature for stirring the adding silane coupling agent is 55-65° C., and the stirring time is 1-2 h.

[0012] As a further technical solution, the dispersant is sodium polyacrylate; and the wetting agent is sodium dodecylnaphthalenesulfonate.

[0013] As a further technical solution, the stabilizer comprises hexamethylenetetramine and diammonium hydrogen phosphate in a weight ratio of 1:3-4.

[0014] In a second aspect, the present invention provides a method for preparing a mancozeb wettable powder, comprising the steps of: mixing mancozeb, attapulgite-diatomaceous earth-nanoalumina composite filler, a dispersant, a wetting agent and a stabilizer at a rotation speed of 1000-1200 rpm for 10-20 minutes, crushing the mixture with a jet mill to a particle size D50 ≤ 5 μm, then mixing the mixture at a rotation speed of 400-500 rpm for 30-40 minutes, and filtering the mixture through a 100-mesh vibrating sieve to obtain the wettable powder.

[0015] The working principle and beneficial effects of the present invention are: The mancozeb wettable powder of the present invention utilizes a composite filler composed of attapulgite, diatomite, and nanoalumina. This composite filler utilizes the complementary hierarchical pore structures of attapulgite and diatomite to significantly enhance the dispersibility and stability of the mancozeb wettable powder. Attapulgite has a one-dimensional nanorod-like structure with micropores and mesopores, while diatomite features a three-dimensional porous siliceous framework rich in macropores and mesopores. When combined, the micropores (attapulgite) adsorb pesticide molecules, while the mesopores and macropores (diatomite) provide rapid mass transfer channels, forming a synergistic "adsorption-diffusion" system. The macropores of the diatomite rapidly capture mancozeb particles, while the micropores of the attapulgite enhance the binding force between the particles and the carrier through capillary action, thereby inhibiting aggregation during storage.

[0016] The present invention pre-treats attapulgite-diatomite by high-temperature calcination and hydrochloric acid impregnation, significantly increasing the specific surface area and pore volume of the carrier. Calcination can remove crystal water and organic impurities (such as cellulose and hemicellulose) in the attapulgite, while promoting the transformation of amorphous SiO2 in the diatomite to a crystalline state. Hydrochloric acid treatment can selectively dissolve Mg in the attapulgite. 2+ 、Al 3+ and Al2O3 impurities in diatomaceous earth to form a mesoporous structure.

[0017] This invention uses a sol-gel method to load nano-alumina onto a pretreated carrier, significantly enhancing the anchoring effect between the filler and the pesticide particles. The nano-alumina particles form a "pinning" structure on the carrier surface, enhancing mechanical interlocking through physical interlocking. The amino group (-NH2) of the silane coupling agent (KH550) can form hydrogen bonds with the hydroxyl groups (-OH) on the surface of the nano-alumina, and at the same time, with the zinc ions (Zn 2+ ) undergoes coordination.

[0018] This invention utilizes a stabilizer compound of methenamine and diammonium phosphate, significantly slowing the hydrolysis of mancozeb through a synergistic effect of decomposition inhibition and pH buffering. Methanamine reacts with the thiol group (-SH) produced by mancozeb hydrolysis to form a stable thioether bond (CSC), while diammonium phosphate ((NH4)2HPO4) maintains buffering capacity within the pH range of 4-8, counteracting the acidic substances produced by mancozeb hydrolysis. DETAILED DESCRIPTION

[0019] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0020] It should be noted that the sodium polyacrylate in the present invention has a CAS number of 9003-04-7 and a model number of 767418 and is purchased from MacLean's reagent.

[0021] Example 1 This embodiment provides a mancozeb wettable powder, which includes the following materials in parts by weight: 83 parts of mancozeb, 9 parts of attapulgite-diatomite-nanoalumina composite filler, 5.5 parts of dispersant, 1.5 parts of wetting agent, and 0.7 parts of stabilizer; The preparation method of the attapulgite-diatomite-nano-alumina composite filler comprises: The attapulgite and diatomite were mixed in a weight ratio of 4.5:1, heated to 590°C at 5°C / min, and then calcined for 2.5 hours. The calcined product was immersed in an 11% hydrochloric acid aqueous solution, stirred at 75°C for 2.5 hours, filtered, washed with deionized water until neutral, and dried at 65°C to constant weight to obtain an attapulgite-diatomite composite substrate; the weight ratio of the calcined product to the hydrochloric acid aqueous solution was 1:3.5; Aluminum isopropoxide and ethanol were mixed in a mass ratio of 1:11, nitric acid was added dropwise to adjust the pH to 4.5, and the mixture was hydrolyzed at 85°C for 3.5 hours to obtain Al(OH)3 sol; the amount of aluminum isopropoxide was 7% of the total mass of attapulgite and diatomite; An attapulgite-diatomite composite substrate was added to an Al(OH)3 sol, stirred at 60°C for 2.5 hours, and then calcined at 525°C for 1.25 hours to obtain an alumina-loaded substrate. The substrate was then dispersed in ethanol, and a silane coupling agent was added. The mixture was stirred at 60°C for 1.5 hours, centrifuged, and dried at 60°C to a constant weight. The silane coupling agent was KH550. The weight ratio of the alumina-loaded substrate, ethanol, and silane coupling agent was 1:5.5:0.07. The dispersant is sodium polyacrylate; the wetting agent is sodium dodecylnaphthalene sulfonate; the stabilizer includes hexamethylenetetramine and diammonium hydrogen phosphate in a weight ratio of 1:3.5; The preparation method of mancozeb wettable powder comprises the following steps: mixing mancozeb, attapulgite-diatomite-nanoalumina composite filler, a dispersant, a wetting agent and a stabilizer at a rotation speed of 1100 rpm for 15 minutes, crushing the mixture with a jet mill to a particle size D50 of 5 μm, then mixing the mixture at a rotation speed of 450 rpm for 35 minutes, and filtering the mixture with a 100-mesh vibrating sieve to obtain the mancozeb wettable powder.

[0022] Example 2 This embodiment provides a mancozeb wettable powder, which includes the following materials in parts by weight: 82 parts of mancozeb, 7 parts of attapulgite-diatomite-nanoalumina composite filler, 5 parts of dispersant, 1 part of wetting agent, and 0.5 parts of stabilizer; The preparation method of the attapulgite-diatomite-nano-alumina composite filler comprises: The attapulgite and diatomite were mixed in a weight ratio of 4:1, heated to 580°C at 4°C / min and calcined for 2 hours. The calcined product was immersed in a 10% hydrochloric acid aqueous solution, stirred at 70°C for 2 hours, filtered, washed with deionized water until neutral, and dried at 60°C to constant weight to obtain an attapulgite-diatomite composite substrate. The weight ratio of the calcined product to the hydrochloric acid aqueous solution was 1:3. Aluminum isopropoxide and ethanol were mixed in a mass ratio of 1:10, nitric acid was added dropwise to adjust the pH to 4, and then hydrolyzed at 80°C for 3 hours to obtain Al(OH)3 sol; the amount of aluminum isopropoxide was 5% of the total mass of attapulgite and diatomite; An attapulgite-diatomite composite substrate was added to an Al(OH)3 sol, stirred at 55°C for 2 hours, and then calcined at 500°C for 1 hour to obtain an alumina-loaded substrate. The substrate was then dispersed in ethanol, and a silane coupling agent was added. The mixture was stirred at 55°C for 1 hour, centrifuged, and dried at 60°C to constant weight. The silane coupling agent was KH550. The weight ratio of the alumina-loaded substrate, ethanol, and silane coupling agent was 1:5:0.05. The dispersant is sodium polyacrylate; the wetting agent is sodium dodecylnaphthalene sulfonate; the stabilizer includes hexamethylenetetramine and diammonium hydrogen phosphate in a weight ratio of 1:3; The preparation method of mancozeb wettable powder comprises the following steps: mixing mancozeb, attapulgite-diatomite-nanoalumina composite filler, dispersant, wetting agent and stabilizer at a rotation speed of 1000 rpm for 10 minutes, crushing the mixture with a jet mill to a particle size D50 of 5 μm, then mixing the mixture at a rotation speed of 400 rpm for 30 minutes, and filtering the mixture with a 100-mesh vibrating sieve to obtain the mancozeb wettable powder.

[0023] Example 3 This embodiment provides a mancozeb wettable powder, which includes the following materials in parts by weight: 85 parts of mancozeb, 10 parts of attapulgite-diatomaceous earth-nanoalumina composite filler, 6 parts of dispersant, 2 parts of wetting agent, and 1 part of stabilizer; The preparation method of the attapulgite-diatomite-nano-alumina composite filler comprises: The attapulgite and diatomite were mixed in a weight ratio of 5:1, heated to 600°C at 6°C / min, and then calcined for 3 hours. The calcined product was immersed in a 12% hydrochloric acid aqueous solution, stirred at 80°C for 3 hours, filtered, washed with deionized water until neutral, and dried at 70°C to constant weight to obtain an attapulgite-diatomite composite substrate; the weight ratio of the calcined product to the hydrochloric acid aqueous solution was 1:4; Aluminum isopropoxide and ethanol were mixed in a mass ratio of 1:12, nitric acid was added dropwise to adjust the pH to 5, and then hydrolyzed at 90°C for 4 hours to obtain Al(OH)3 sol; the amount of aluminum isopropoxide was 10% of the total mass of attapulgite and diatomite; An attapulgite-diatomite composite substrate was added to an Al(OH)3 sol, stirred at 65°C for 3 hours, and then calcined at 550°C for 1.5 hours to obtain an alumina-loaded substrate. The substrate was then dispersed in ethanol, and a silane coupling agent was added. The mixture was stirred at 65°C for 2 hours, centrifuged, and dried at 60°C to a constant weight. The silane coupling agent was KH550. The weight ratio of the alumina-loaded substrate, ethanol, and silane coupling agent was 1:6:0.1. The dispersant is sodium polyacrylate; the wetting agent is sodium dodecylnaphthalene sulfonate; the stabilizer includes hexamethylenetetramine and diammonium hydrogen phosphate in a weight ratio of 1:4; The preparation method of mancozeb wettable powder comprises the following steps: mixing mancozeb, attapulgite-diatomite-nanoalumina composite filler, dispersant, wetting agent and stabilizer at a rotation speed of 1200 rpm for 20 minutes, crushing the mixture with a jet mill to a particle size D50 of 5 μm, then mixing the mixture at a rotation speed of 500 rpm for 40 minutes, and filtering the mixture with a 100-mesh vibrating sieve to obtain the mancozeb wettable powder.

[0024] Example 4 This embodiment provides a mancozeb wettable powder, which includes the following materials in parts by weight: 82 parts of mancozeb, 10 parts of attapulgite-diatomite-nanoalumina composite filler, 5 parts of dispersant, 2 parts of wetting agent, and 0.5 parts of stabilizer; The preparation method of the attapulgite-diatomite-nano-alumina composite filler comprises: The attapulgite and diatomite were mixed in a weight ratio of 5:1, heated to 600°C at 4°C / min, and then calcined for 2 hours. The calcined product was immersed in a 12% hydrochloric acid aqueous solution, stirred at 70°C for 3 hours, filtered, washed with deionized water until neutral, and dried at 60°C to constant weight to obtain an attapulgite-diatomite composite substrate; the weight ratio of the calcined product to the hydrochloric acid aqueous solution was 1:4; Aluminum isopropoxide and ethanol were mixed in a mass ratio of 1:10, nitric acid was added dropwise to adjust the pH to 5, and then hydrolyzed at 80°C for 4 hours to obtain Al(OH)3 sol; the amount of aluminum isopropoxide was 7% of the total mass of attapulgite and diatomite; An attapulgite-diatomite composite substrate was added to an Al(OH)3 sol, stirred at 55°C for 3 hours, and then calcined at 500°C for 1.5 hours to obtain an alumina-loaded substrate. The substrate was then dispersed in ethanol, and a silane coupling agent was added. The mixture was stirred at 55°C for 2 hours, centrifuged, and dried at 60°C to a constant weight. The silane coupling agent was KH550. The weight ratio of the alumina-loaded substrate, ethanol, and silane coupling agent was 1:5:0.1. The dispersant is sodium polyacrylate; the wetting agent is sodium dodecylnaphthalene sulfonate; the stabilizer includes hexamethylenetetramine and diammonium hydrogen phosphate in a weight ratio of 1:3; The method for preparing a mancozeb wettable powder comprises the following steps: mixing mancozeb, attapulgite-diatomite-nanoalumina composite filler, a dispersant, a wetting agent and a stabilizer at a rotation speed of 1200 rpm for 10 minutes, crushing the mixture with a jet mill to a particle size D50 of 5 μm, then mixing the mixture at a rotation speed of 500 rpm for 30 minutes, and filtering the mixture with a 100-mesh vibrating sieve to obtain the mancozeb wettable powder.

[0025] Comparative Example 1 In Comparative Example 1, the attapulgite in the composite filler raw material was replaced with diatomaceous earth of equal mass; the rest was the same as in Example 1, and the preparation steps were the same as in Example 1.

[0026] Comparative Example 2 In Comparative Example 2, the diatomaceous earth in the composite filler raw material was replaced with attapulgite of equal mass, and the rest was the same as in Example 1, and the preparation steps were the same as in Example 1.

[0027] Comparative Example 3 The preparation method of the attapulgite-diatomite-nanoalumina composite filler in Comparative Example 3 includes: mixing attapulgite and diatomite in a weight ratio of 4.5:1, heating to 590°C at 5°C / min and calcining for 2.5h, immersing the calcined product in an 11% mass fraction hydrochloric acid aqueous solution, stirring at 75°C for 2.5h, filtering, washing with deionized water to neutrality, and drying at 65°C to constant weight to obtain a attapulgite-diatomite composite substrate; calcining The weight ratio of the calcined product and the hydrochloric acid aqueous solution is 1:3.5; the prepared attapulgite-diatomite composite substrate is then dispersed in ethanol, a silane coupling agent is added, stirred at 60°C for 1.5 hours, centrifuged, and dried at 60°C to constant weight; the silane coupling agent is KH550; the weight ratio of the attapulgite-diatomite composite substrate, ethanol and silane coupling agent is 1:5.5:0.07; the rest is the same as in Example 1, and the preparation steps are the same as in Example 1.

[0028] Comparative Example 4 The preparation method of the composite filler in Comparative Example 4 includes: mixing attapulgite and diatomaceous earth in a weight ratio of 4.5:1, mixing aluminum isopropoxide and ethanol in a mass ratio of 1:11, adding nitric acid dropwise to adjust the pH to 4.5, and hydrolyzing at 85°C for 3.5 hours to obtain Al(OH)3 sol; aluminum isopropoxide is 7% of the total mass of attapulgite and diatomaceous earth; adding the attapulgite and diatomaceous earth mixture to the Al(OH)3 sol, stirring and mixing at 60°C for 2.5 hours, and then calcining at 525°C for 1.25 hours to obtain an alumina-loaded substrate, which is then dispersed in ethanol, added with a silane coupling agent, stirred at 60°C for 1.5 hours, centrifuged, and dried at 60°C to constant weight; the silane coupling agent is KH550; the weight ratio of the alumina-loaded substrate, ethanol and silane coupling agent is 1:5.5:0.07, and the rest is the same as in Example 1, and the preparation steps are the same as in Example 1.

[0029] Comparative Example 5 In Comparative Example 5, the stabilizer is hexamethylenetetramine, and the rest is the same as in Example 1, and the preparation steps are the same as in Example 1.

[0030] Comparative Example 6 In Comparative Example 6, the stabilizer is diammonium hydrogen phosphate, and the rest is the same as in Example 1, and the preparation steps are the same as in Example 1.

[0031] Test Example 1: The following tests were performed on the mancozeb wettable powders prepared in Examples 1-4 and Comparative Examples 1-6: Suspension rate: Refer to GB / T 14825-2006: add 1g sample to 342mg / L hard water, stir and let stand for 30min, take the upper liquid to determine the mancozeb content; Wetting time: refer to GB / T5451-2001; Cold storage stability: Freeze at -20℃ for 24 hours, then return to room temperature and observe for agglomeration and stratification. Long-term storage stability: Store sealed at room temperature (25°C) for 12 months, test the suspension rate of the sample and calculate the rate of decline; The results are shown in Table 1 below: Table 1

[0032] Combined with the above, it can be seen that the synergistic effect of attapulgite and diatomite significantly improves performance. Comparative Examples 1-2 show that using a single component leads to a reduced suspension rate and prolonged wetting time, indicating that the complementary multi-level pore structures of the two are crucial for dispersibility and stability. The suspension rate of Comparative Example 3 decreased by 7.4%, indicating that nano-alumina, by improving surface roughness and chemical bonding ability, strengthens the anchoring effect between the filler and the pesticide particles and reduces storage agglomeration. The suspension rate of Comparative Example 4 decreased by 10.1%, demonstrating that high-temperature calcination can remove organic impurities, acid etching and pore expansion, and increase the specific surface area of the carrier, while nano-alumina loading requires a pre-treated active surface. The suspension rate reduction rate of Comparative Examples 5-6, with a single stabilizer, is significantly higher than that of the examples, demonstrating that the combination of hexamethylenetetramine and diammonium hydrogen phosphate can synergistically delay the hydrolysis of mancozeb and maintain system stability.

[0033] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A mancozeb wettable powder, characterized in that, The invention comprises the following materials in parts by weight: 82-85 parts of mancozeb, 7-10 parts of attapulgite-diatomite-nano alumina composite filler, 5-6 parts of dispersant, 1-2 parts of wetting agent and 0.5-1 part of stabilizer.

2. A mancozeb wettable powder according to claim 1, characterized in that, The preparation method of the attapulgite-diatomite-nanoalumina composite filler includes: mixing attapulgite and diatomite, calcining them, and then immersing them in a hydrochloric acid solution to prepare an attapulgite-diatomite composite substrate; adding the attapulgite-diatomite composite substrate to an Al(OH)3 sol, stirring and mixing at 55-65°C for 2-3 hours, and calcining at 500-550°C for 1-1.5 hours to obtain an alumina-loaded substrate, which is then dispersed in ethanol, and a silane coupling agent is added, stirred, and centrifuged to obtain the substrate.

3. A mancozeb wettable powder according to claim 2, characterized in that, The preparation method of the attapulgite-diatomite composite substrate includes: mixing attapulgite and diatomite in a weight ratio of 4-5:1, heating to 580-600°C at 4-6°C / min, and then calcining for 2-3 hours, immersing the calcined product in a hydrochloric acid aqueous solution with a mass fraction of 10%-12%, stirring and reacting at 70-80°C for 2-3 hours, filtering, washing with deionized water to neutrality, and drying at 60-70°C to constant weight to obtain the attapulgite-diatomite composite substrate; the weight ratio of the calcined product to the hydrochloric acid aqueous solution is 1:3-4.

4. A mancozeb wettable powder according to claim 2, characterized in that, The preparation method of the Al(OH)3 sol comprises: mixing aluminum isopropoxide and ethanol in a mass ratio of 1:10-12, adding nitric acid dropwise to adjust the pH to 4-5, and hydrolyzing at 80-90°C for 3-4h to obtain the Al(OH)3 sol.

5. A mancozeb wettable powder according to claim 4, characterized in that, The aluminum isopropoxide is 5%-10% of the total mass of attapulgite and diatomaceous earth.

6. A mancozeb wettable powder according to claim 2, characterized in that, The silane coupling agent is KH550; the weight ratio of the alumina-loaded substrate, ethanol and the silane coupling agent is 1:5-6:0.05-0.

1.

7. A mancozeb wettable powder according to claim 2, characterized in that, The temperature for adding the silane coupling agent and stirring is 55-65° C., and the stirring time is 1-2 hours.

8. A mancozeb wettable powder according to claim 1, characterized in that, The dispersant is sodium polyacrylate; the wetting agent is sodium dodecylnaphthalene sulfonate.

9. A mancozeb wettable powder according to claim 1, characterized in that, The stabilizer comprises hexamethylenetetramine and diammonium hydrogen phosphate in a weight ratio of 1:3-4.

10. A method for preparing the mancozeb wettable powder according to any one of claims 1 to 9, characterized in that the steps include: Mancozeb, attapulgite-diatomite-nano alumina composite filler, dispersant, wetting agent and stabilizer are mixed at a rotation speed of 1000-1200 rpm for 10-20 minutes, crushed by a jet mill to a particle size D50≤5 μm, then mixed at a rotation speed of 400-500 rpm for 30-40 minutes, and filtered through a 100-mesh vibration sieve to obtain the product.

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