A carbendazim wettable powder and its preparation method and application

Abstract

The present application relates to the technical field of carbendazim wettable powder pesticides, more specifically, it relates to a carbendazim wettable powder and its preparation method and application, specifically including the following raw materials in mass percentage, 45-50wt% carbendazim, 0.5-2wt% wetting agent, 3-10wt% auxiliary dispersant a, 3-10wt% auxiliary dispersant b, and the balance is filler; carbendazim, wetting agent, auxiliary dispersant a are weighed by weight percentage, auxiliary dispersant b and filler are mixed and sieved to obtain carbendazim wettable powder, and the carbendazim wettable powder of the present application is used for the prevention and treatment of vegetable sclerotinia. The carboxyl group contained in the auxiliary dispersant a in the present application has strong hydrophilicity and increases the dispersibility of the substance in water. The auxiliary dispersant b of the present application can interact with carbendazim microscopically to increase the dispersibility of carbendazim in water. The present application improves the dispersibility of carbendazim wettable powder in water and enhances the bactericidal ability through the synergistic effect of auxiliary dispersant a, auxiliary dispersant b and wetting agent.

Description

Technical Field

[0001] The present application relates to the technical field of carbendazim wettable powder pesticides, and more specifically, to a carbendazim wettable powder and a preparation method and application thereof. Background Art

[0002] Vegetables are an indispensable dish on the table in the lives of residents nowadays. They provide people with a variety of vitamins, improve human immunity, and improve the health of residents. However, in the process of growing vegetables, in addition to inevitable natural disasters, insect pests are also a major threat to the growth of vegetables. If there are fewer insect pests, the income of vegetable farmers will be greatly reduced, and if there are more insect pests, vegetable farmers will have no income. Therefore, avoiding insect pests is the top priority in vegetable planting. As a broad-spectrum fungicide, carbendazim is widely popular. Carbendazim is also known as cotton wilt, benzimidazole 44, and its chemical name is N-(2-benzoimidazole)-methyl carbamate. Carbendazim is a highly efficient and low-toxic systemic fungicide with systemic treatment and protective effects. It has a preventive and control effect on diseases caused by fungi (such as Ascomycetes and Polyascomycetes) in various crops. The principle is to interfere with the formation of spindles in the mitosis of pathogens, affect cell division, and then play a bactericidal role. Carbendazim can be used for foliar spraying, seed treatment and soil treatment. Carbendazim is inexpensive, easy to use, highly effective and low in toxicity, so it is widely popular. However, carbendazim also has some shortcomings. For example, the various raw materials have poor dispersion during the mixing process, which directly leads to uneven mixing and affects the sterilization efficiency. Therefore, many scholars have continuously tried to develop a carbendazim wettable powder with good dispersion effect and efficient sterilization in response to the shortcomings of carbendazim.

[0003] The Chinese patent with the announcement number CN101828568B discloses a carbendazim water dispersible granule, the main content of which is to mix 85% to 95% of carbendazim original drug, 2% to 5% of dispersant, 1% to 3% of surfactant, 1% to 3% of wetting agent and 1% to 4% of filler according to weight percentage. The technical document uses D450 and YUS-WG4 as dispersants and reduces the content of fillers, thereby achieving high efficacy, good stability, good disintegration, and good fluidity, no caking, and no sticking to the wall. However, the YUS-WG4 in the technical document belongs to a lignin dispersant, which is not modified during use, so it may affect the dispersion effect of the carbendazim agent.

[0004] A Chinese patent with announcement number CN 110037043 A discloses a carbendazim wettable powder and a preparation process thereof, which is specifically made of the following raw materials in the following mass percentages: 36% to 42% carbendazim, 0.5% to 1.8% wetting agent, 7.2% to 7.8% dispersant and 12% to 32% filler. The dispersant in the technical document is prepared from pulping black liquor. By adding phenol or phenol derivatives, the dispersant activity of lignin can be improved to a certain extent, thereby improving its dispersibility. However, the preparation process is relatively complicated, which means that there will be many side reactions and the introduction of other by-products may reduce the bactericidal effect. At the same time, these by-products may pollute the environment.

[0005] Wood mainly contains cellulose, hemicellulose and lignin, but in the papermaking industry, the presence of lignin will affect the strength and color of paper, because when making paper, lignin must be removed. The common methods for extracting cellulose and hemicellulose are alkaline or acid treatment, which produces pulping black liquor, the main component of which is lignin, and a small amount of starch, resin and other organic matter. If it is discharged directly into the river without treatment, it will seriously pollute the environment. Therefore, if we can make full use of the lignin in the pulping black liquor and realize waste utilization, it will not only protect the environment but also save resources.

[0006] In summary, the present application provides a carbendazim wettable powder and a preparation method and application thereof, aiming to improve the above-mentioned problems. Summary of the invention

[0007] In order to improve the problem of uneven mixing of various raw materials of carbendazim in the background technology and poor dispersion performance, the present application provides a carbendazim wettable powder and a preparation method and application thereof.

[0008] In the first aspect, the present application provides a carbendazim wettable powder, which adopts the following technical solution:

[0009] A carbendazim wettable powder comprises the following components in percentage by mass:

[0010] 45-50wt% carbendazim, 0.5-2wt% wetting agent, 3-10wt% auxiliary dispersant a, 3-10wt% auxiliary dispersant b, and the balance is filler;

[0011] Wherein, the auxiliary dispersant a contains a carboxyl group, and the auxiliary dispersant b is a modified lignin-based dispersant.

[0012] In a specific embodiment, the wetting agent is any one of sodium dodecylbenzenesulfonate or sodium isopropyl naphthalenesulfonate.

[0013] In a specific embodiment, the filler is any one or more of diatomaceous earth, diatomaceous earth, kaolin, white carbon black, talc, montmorillonite and corn starch.

[0014] In a specific embodiment, the auxiliary dispersant a is sodium polycarboxylate.

[0015] In a specific embodiment, the auxiliary dispersant b is prepared as follows:

[0016] S1. Mix the pulping black liquor and the oxidant, and react at 60-75°C for 1-1.5h to obtain liquid A;

[0017] S2. Add aldehyde compounds to the solution A obtained in S1, adjust the pH value to 9-11, and react at 60-90°C for 2-3h to obtain solution B.

[0018] S3. Add sulfonating agent to liquid B obtained in S2, adjust the pH value to 4-6, react at 70-95°C for 2.5-4h, then let stand to room temperature, dry, grind and sieve to obtain auxiliary dispersant b.

[0019] In a specific implementation scheme, the pulping black liquor in S1 is prepared from any one or more of bamboo, wood or straw by an alkaline method, the oxidant is any one of hydrogen peroxide, potassium permanganate, potassium dichromate or potassium iodate, and the mass ratio of the pulping black liquor to the oxidant is (60~70):1.

[0020] In a specific implementation manner, the aldehyde compound in S2 is any one of formaldehyde, acetaldehyde, urea or acrylic acid, and the mass ratio of the A liquid to the aldehyde compound is (40-60):1.

[0021] In a specific implementation scheme, the sulfonating agent in S3 is any one of sulfite, aminosulfonic acid or chlorosulfonic acid, and the mass ratio of the B liquid to the sulfonating agent is (30~50):1.

[0022] In a second aspect, the present application also provides a method for preparing a carbendazim wettable powder, using the following technical solution:

[0023] Weigh carbendazim, wetting agent, auxiliary dispersant a, auxiliary dispersant b and filler according to weight percentage, mix evenly and sieve to obtain carbendazim wettable powder.

[0024] In a third aspect, the present application also provides an application of a carbendazim wettable powder for the prevention and treatment of vegetable sclerotinia disease.

[0025] This application has the following beneficial effects:

[0026] The auxiliary dispersant a in the present application contains a carboxyl group, which has strong hydrophilicity and increases the dispersibility of the substance in water. The auxiliary dispersant b in the present application is lignin extracted from pulping black liquor. Lignin is a natural substance and has a benzene ring structure. The benzene ring is a six-membered ring compound with a special π bond structure. In the benzene ring, each carbon atom shares a sp with two adjacent carbon atoms. 2 hybrid orbital, while the remaining one sp 2 The hybridized orbit forms a covalent bond with the hydrogen atom, and the presence of the π bond also makes the benzene ring have a certain electron affinity and nucleophilicity, which can interact with carbendazim at the microscopic level to increase the dispersibility of carbendazim in water. At the same time, the lignin modified by the sulfonating agent has an increased molecular weight, enhanced water solubility and surface activity, which not only realizes the recycling of resources, reduces production costs, reduces environmental pollution, but also further increases the dispersibility of carbendazim wettable powder. The present application improves the dispersibility of carbendazim in water and enhances its bactericidal ability through the synergistic effect of auxiliary dispersants a, auxiliary dispersants b and wetting agents. DETAILED DESCRIPTION

[0027] The present application is further described in detail below with reference to the embodiments.

[0028] Carbendazim is a highly efficient, low-toxic, broad-spectrum, systemic fungicide with protective and therapeutic effects. It can penetrate into the plant body through the leaves, and has the characteristics of being resistant to rainwater erosion and having a long lasting effect. It is active against a variety of pathogens in ascomycetes, basidiomycetes and deuteromycetes. It is mainly used to prevent and treat a variety of fungal diseases in grain, cotton, oil, fruit, vegetables, and flowers, and can also be used for the preservation of fruits. Carbendazim powder is commonly used, and when used, carbendazim powder and water are usually mixed in a certain proportion, and then sprayed for use. However, the applicant found the following problems during use: because the powder has poor dispersibility when dissolved in water, it seriously affects the effect of its pest control. At the same time, due to the poor dispersibility, these fine particles in the water will agglomerate, which will cause the spray hole to be blocked during spraying, and accessories need to be frequently replaced, and even related equipment is damaged. Therefore, the applicant has been trying to find a better dispersant. Through a large number of search documents and the applicant's many years of research and development experience in this field, based on the fact that the main component of carbendazim is N-(2-benzoimidazole)-methyl carbamate, which is a lipid substance and insoluble in water, it is necessary to introduce a hydrophilic group. After a large number of screening and attempts, it was found that when the dispersant contains a carboxyl group, it has a strong hydrophilicity and increases the dispersibility of the substance in water. However, the applicant found that if only one dispersant is selected, firstly, this dispersing functional group is less and the dispersing effect cannot meet the ideal requirements. Secondly, the substance needs to be purchased, which is not suitable from the perspective of long-term development and corporate interests. Therefore, the applicant tried to find a natural substance that can synergize with dispersant a to increase the dispersibility of carbendazim. The applicant consulted well-known experts in the field and conducted multiple experiments with the research and development team to prepare a modified lignin-based dispersant. It was found that the modified lignin-based dispersant and the auxiliary dispersant a cooperated with each other to greatly increase the dispersing effect of carbendazim. This may be because lignin is a natural substance and has a benzene ring structure. The benzene ring is a six-membered ring compound with a special π bond structure. In the benzene ring, each carbon atom shares a sp with two adjacent carbon atoms. 2 hybrid orbital, while the remaining one sp 2The hybridized orbital forms a covalent bond with the hydrogen atom. This structure makes the carbon atoms in the benzene ring no longer exist on the same plane as in methane or ethylene, but forms a distorted structure. This structure not only brings unique properties to the benzene ring, but also profoundly affects the π bond structure in the benzene ring. The presence of the π bond also makes the benzene ring have a certain electron affinity and nucleophilicity, so the dispersant and N-(2-phenylimidazolyl)-methyl carbamate can increase the dispersibility of N-(2-phenylimidazolyl)-methyl carbamate in water through microscopic interaction. The applicant also found that when selecting a wetting agent, sodium dodecylbenzene sulfonate and sodium isopropyl naphthalene sulfonate were selected because these substances have good hydrophilicity and lipophilicity, which further increases the dispersibility of carbendazim, and both substances have benzene rings, which can work together with dispersant b to increase the dispersibility of carbendazim again. The fillers selected in the present application are diatomaceous earth, kieselguhr, kaolin, white carbon black, talcum powder, montmorillonite and corn starch. These fillers are all natural and pollution-free. Even if they are sprayed into the environment, they will not cause certain pollution to the environment. At the same time, these materials are low in price and easy to purchase.

[0029] In summary, the auxiliary dispersant a in the present application contains a carboxyl group, which has strong hydrophilicity and increases the dispersibility of the substance in water. The auxiliary dispersant b in the present application is lignin extracted from pulping black liquor. Lignin is a natural substance and has a benzene ring structure. The benzene ring is a six-membered ring compound with a special π bond structure. In the benzene ring, each carbon atom shares a sp with two adjacent carbon atoms. 2 hybrid orbital, while the remaining one sp 2 The hybridized orbit forms a covalent bond with the hydrogen atom, and the presence of the π bond also makes the benzene ring have a certain electron affinity and nucleophilicity, which can interact with carbendazim at the microscopic level to increase the dispersibility of carbendazim in water. At the same time, the lignin modified by the sulfonating agent has an increased molecular weight, enhanced water solubility and surface activity, which not only realizes the recycling of resources, reduces production costs, reduces environmental pollution, but also further increases the dispersibility of carbendazim wettable powder. The present application improves the dispersibility of carbendazim in water and enhances its bactericidal ability through the synergistic effect of auxiliary dispersants a, auxiliary dispersants b and wetting agents.

[0030] The solution of the present application is further explained below in conjunction with specific embodiments.

[0031] Preparation of auxiliary dispersant method 1: S1. Oxidation reaction: Take pulping black liquor from a paper mill in Zhejiang Province. The mill mainly uses pine wood as papermaking raw material. Put the pulping black liquor and hydrogen peroxide in a constant temperature water bath at a mass ratio of 65:1. Control the temperature to 65°C, set the speed to 200r / min, and stir the reaction for 1.2h to obtain liquid A.

[0032] S2. Condensation reaction: add formaldehyde solution to the solution A obtained in S1, control the mass ratio of solution A to formaldehyde solution to be 50:1, adjust the pH value to 10 with aqueous ammonia, control the temperature to 75°C, the speed to 200 r / min, and stir the reaction for 2.5 h to obtain solution B;

[0033] S3. Sulfonation reaction: add sodium sulfite to the liquid B obtained in S2, control the mass ratio of liquid B to sodium sulfite to be 40:1, adjust the pH value to 5 with sulfuric acid, control the temperature to 85°C, the rotation speed to 200r / min, stir and react for 3h, then let it stand to room temperature, spray dry, and then grind it with an XD-20-65T three-roller nano-disperser. In order to prevent the nanomaterial from agglomerating, the ground powder is sieved through a 400-mesh sieve to obtain an auxiliary dispersant b1.

[0034] Preparation method 2 of auxiliary dispersant: S1. Oxidation reaction: Take pulping black liquor from a paper mill in Zhejiang Province. The mill mainly uses pine wood as papermaking raw material. Put the pulping black liquor and potassium permanganate in a constant temperature water bath at a mass ratio of 60:1. Control the temperature to 75°C, set the speed to 200r / min, and stir for 1h to obtain liquid A.

[0035] S2. Condensation reaction: urea was added to the solution A obtained in S1, the mass ratio of solution A to urea solution was controlled to be 40:1, the pH value was adjusted to 11 with aqueous ammonia, the temperature was controlled to be 90°C, the speed was 200 r / min, and the reaction was stirred for 2.5 h to obtain solution B;

[0036] S3. Sulfonation reaction: Add sulfamic acid to the liquid B obtained in S2, control the mass ratio of liquid B to sulfamic acid to be 50:1, adjust the pH value to 6 with sulfuric acid, control the temperature to 95°C, the rotation speed to 200r / min, stir and react for 2h, then let it stand to room temperature, spray dry, and then grind it with an XD-20-65T three-roller nano-disperser. In order to prevent the nanomaterial from agglomerating, the ground powder is sieved through a 400-mesh sieve to obtain an auxiliary dispersant b2.

[0037] Preparation method 3 of auxiliary dispersant: S1. Oxidation reaction: Take pulping black liquor from a paper mill in Zhejiang Province. The mill mainly uses pine wood as papermaking raw material. Put the pulping black liquor and potassium iodate in a constant temperature water bath at a mass ratio of 70:1. Control the temperature at 60°C, set the speed at 200r / min, and stir the reaction for 1.5h to obtain liquid A.

[0038] S2. Condensation reaction: add acetaldehyde solution to the solution A obtained in S1, control the mass ratio of solution A to acetaldehyde solution to 60:1, adjust the pH value to 9 with aqueous ammonia, control the temperature to 60 ° C, the speed to 200 r / min, and stir the reaction for 3h to obtain solution B;

[0039] S3. Sulfonation reaction: add chlorosulfonic acid to the liquid B obtained in S2, control the mass ratio of liquid B to chlorosulfonic acid to be 30:1, adjust the pH value to 4 with sulfuric acid, control the temperature to 70°C, the rotation speed to 200r / min, stir and react for 4h, then let it stand to room temperature, spray dry, and then grind with an XD-20-65T three-roller nano-disperser. In order to prevent the nanomaterial from agglomerating, the ground powder is sieved through a 400-mesh sieve to obtain an auxiliary dispersant b3.

[0040] Preparation method 4 of auxiliary dispersant: S1. Oxidation reaction: Take pulping black liquor from a paper mill in Zhejiang Province. The mill mainly uses pine wood as papermaking raw material. Put the pulping black liquor and potassium dichromate in a constant temperature water bath at a mass ratio of 65:1. Control the temperature to 70°C, set the speed to 200r / min, and stir the reaction for 1.3h to obtain liquid A.

[0041] S2. Condensation reaction: Add acrylic acid solution to the solution A obtained in S1, control the mass ratio of solution A to acrylic acid solution to 60:1, adjust the pH value to 10 with aqueous ammonia, control the temperature to 80 ° C, the speed to 200 r / min, and stir the reaction for 2.6 h to obtain solution B;

[0042] S3. Sulfonation reaction: add potassium sulfite to the liquid B obtained in S2, control the mass ratio of liquid B to potassium sulfite to be 45:1, adjust the pH value to 5 with sulfuric acid, control the temperature to 83°C, the rotation speed to 200r / min, stir the reaction for 3.5h, then let it stand to room temperature, spray dry, and then grind it with an XD-20-65T three-roller nano-disperser. In order to prevent the nanomaterial from agglomerating, the ground powder is sieved through a 400-mesh sieve to obtain an auxiliary dispersant b4.

[0043] The raw materials or drugs and methods used in preparing auxiliary dispersants in methods 1 to 4 are shown in Table 1.

[0044] Table 1

[0045]

[0046] Example 1: 45 wt% of carbendazim, 1 wt% of wetting agent, 8 wt% of auxiliary dispersant a, 10 wt% of auxiliary dispersant b1 and the remainder of filler were weighed and added into a mixer and mixed for 30 min. After mixing evenly, the mixture was sieved through a 400-mesh sieve to obtain a carbendazim wettable powder.

[0047] The wetting agent used in this embodiment is sodium dodecylbenzene sulfonate, and the filler used is diatomaceous earth and kaolin mixed in a mass ratio of 1:1.

[0048] Example 2: 47 wt% of carbendazim, 0.5 wt% of wetting agent, 3 wt% of auxiliary dispersant a, 5 wt% of auxiliary dispersant b1 and the remainder of filler were weighed and added into a mixer and mixed for 30 min. After mixing evenly, the mixture was passed through a 400 mesh sieve to obtain a carbendazim wettable powder.

[0049] The wetting agent used in this embodiment is sodium dodecylbenzene sulfonate, and the filler used is diatomaceous earth and kaolin mixed in a mass ratio of 1:1.

[0050] Example 3: 48 wt% of carbendazim, 1.5 wt% of wetting agent, 8 wt% of auxiliary dispersant a, 10 wt% of auxiliary dispersant b1 and the remainder of filler were weighed and added into a mixer and mixed for 30 min. After mixing evenly, the mixture was sieved through a 400-mesh sieve to obtain a carbendazim wettable powder.

[0051] Among them, the wetting agent selected in this embodiment is sodium isopropyl naphthalene sulfonate, and the filler selected is white carbon black.

[0052] Example 4: 50 wt% of carbendazim, 2 wt% of wetting agent, 10 wt% of auxiliary dispersant a, 8 wt% of auxiliary dispersant b1 and the remainder of filler were weighed and added into a mixer and mixed for 30 min. After mixing evenly, the mixture was passed through a 400 mesh sieve to obtain a carbendazim wettable powder.

[0053] Among them, the wetting agent selected in this embodiment is sodium isopropyl naphthalene sulfonate, and the filler selected is diatomaceous earth and kaolin corn starch compounded in a mass ratio of 1:1:1.

[0054] Example 5: The main difference between this example and Example 1 is that the auxiliary dispersant selected in this example is the auxiliary dispersant b2 of Preparation Example 2.

[0055] Example 6: The main difference between this example and Example 1 is that the auxiliary dispersant selected in this example is the auxiliary dispersant b3 of Preparation Example 3.

[0056] Example 7: The main difference between this example and Example 1 is that the auxiliary dispersant selected in this example is the auxiliary dispersant b4 of Preparation Example 4.

[0057] Embodiment 8: The main difference between this embodiment and embodiment 1 is that the auxiliary dispersant selected in this embodiment is only auxiliary dispersant a.

[0058] Example 9: The main difference between this example and Example 1 is that the auxiliary dispersant selected in this example is only auxiliary dispersant b.

[0059] Example 10: The main difference between this example and Example 1 is that the auxiliary dispersant b used in this example is the unmodified auxiliary dispersant b5.

[0060] Comparative Example 1: The main difference between this comparative example and Example 1 is that the technical solution in the announcement number CN 110037043 A is selected to prepare the auxiliary dispersant b, which is marked as auxiliary dispersant b6.

[0061] It should be noted that, except for the self-made auxiliary dispersant b, all other reagents involved in Examples 1-7, Examples 8-10 and Comparative Example 1 are commercially available.

[0062] Performance testing: Determination of dispersion index of auxiliary dispersant B:

[0063] The dispersion index method was used to determine the dispersibility of the auxiliary dispersant b, wherein the larger the dispersion index (LSDP), the weaker its dispersibility, as shown in Table 2.

[0064] Table 2

[0065]

[0066] (1) Determination of wettability of carbendazim wettable powder: The wettability of carbendazim wettable powder was determined by referring to the method in “Determination of wettability of pesticide wettable powder (GB / T5451-2001)”. The results are shown in Table 3.

[0067] Table 3

[0068]

[0069] (2) Actual bactericidal effect of carbendazim wettable powder: Based on the wetting results of carbendazim wettable powder, the carbendazim wettable powder prepared in Example 2, Example 8, Example 9, Example 10 and Comparative Example 1 was selected for field test. A rapeseed field in a greenhouse in Shandong Province was selected for the test to test the bactericidal effect. Rapeseed is divided into spring rapeseed and autumn rapeseed. Spring rapeseed is sown from March to May, and autumn rapeseed is sown from September to November. In this test, rapeseed was sown in October in autumn. The rapeseed was sown in June and June, and the experimental field was divided into 6 fields, among which No. 1 rapeseed field was used as a blank control group. During the growth process, except for normal management, no treatment was sprayed with carbendazim wettable powder; No. 2 rapeseed field was sprayed with the carbendazim wettable powder of Example 2; No. 3 rapeseed field was sprayed with the carbendazim wettable powder of Example 8; No. 4 rapeseed was only sprayed with the carbendazim wettable powder of Example 9; No. 5 rapeseed field was sprayed with the carbendazim wettable powder of Example 10, and No. 6 rapeseed field was sprayed with the carbendazim wettable powder of Comparative Example 1.

[0070] The appearance of rapeseed is an important indicator of maturity. Mature rapeseed is yellow-green in appearance, with older leaves and thicker stems. The rapeseed is harvested, and the diseased rapeseed is removed. The per-acre yield of rapeseed is calculated. The per-acre yield of rapeseed fields 1-6 is shown in Table 4.

[0071] Table 4

[0072]

[0073] Result analysis:

[0074] It can be seen from Tables 2 and 3 that the homemade dispersant in this application has good dispersibility and wettability, with a dispersion coefficient below 14.2 and a wettability above 97%, and can evenly disperse the carbendazim wettable powder in water. This may be because the molecular weight of the modified lignin increases, the water solubility and surface activity are enhanced, and it has strong hydrophilicity. At the same time, the auxiliary dispersant a selected in this application contains a carboxyl group, which has strong hydrophilicity and can synergize with the auxiliary dispersant b to increase the water dispersibility of the substance. Further, the three substances of the homemade auxiliary dispersant b and auxiliary dispersant a and wetting agent in this application can synergize to further enhance the wettability and dispersibility of the carbendazim wettable dispersant in water, but by comparison, it can be found that the wettability and dispersibility of the unmodified lignin-based dispersant are slightly worse, and the performance is not much different from that of the commercially available ones. The dispersion effect of the unmodified lignin-based dispersant, only the auxiliary dispersant a, only the auxiliary dispersant b and the auxiliary dispersant prepared by the comparative technical documents is worse. Through field tests, it can be found that only the carbendazim wettable powder prepared in Example 2 has the best effect, indicating that the auxiliary dispersant b and auxiliary dispersant a prepared in this application and the wetting agent work synergistically with each other to enhance the dispersibility of the carbendazim wettable powder and improve the bactericidal ability. The per mu yield of rapeseed fields No. 3-6 is lower than that of rapeseed field No. 2, which may be because the carbendazim wettable powder agglomerates, thus affecting its bactericidal effect.

[0075] The following points should be noted when using the carbendazim wettable powder in this application:

[0076] (1) The carbendazim wettable powder of the present application is used to control rapeseed sclerotinia;

[0077] (2) Start using the drug at the early stage of the disease of rapeseed sclerotinia, and apply it 2 to 3 times at intervals of 7 to 10 days. Make sure to use enough water when spraying, and spray the entire plant evenly. Apply the drug in the morning and evening when the temperature is suitable and there is no wind. Do not apply the drug on windy days or when it is expected to rain within 1 hour.

[0078] (3) This product belongs to the benzimidazole class of low-toxic, systemic fungicides with a long lasting effect. It has a good effect on rapeseed sclerotinia caused by ascomycetes and ascomycetes. Its mechanism of action is mainly to interfere with the formation of spindles in the mitosis of bacteria, thereby affecting cell division, and has a protective and therapeutic effect.

[0079] (4) The product can be used up to 3 times per crop season, with a safe interval of 40 days, that is, it is prohibited to use it 40 days before the crop is harvested; the product of this application cannot be mixed with alkaline pesticides and other substances. Long-term use can easily cause the bacteria to develop drug resistance. In order to delay the occurrence of drug resistance in the disease-causing bacteria, it should be used in rotation with other fungicides; the product of this application has a slight irritating effect on the eyes. When applying the pesticide, the pesticide safety operation procedures should be strictly followed to avoid direct contact between the drug and the eyes, and protective equipment such as masks and gloves should be worn. Smoking and eating are strictly prohibited. The skin and clothes should be washed in time after use; the product of this application must not pollute water sources when applying the pesticide. It is prohibited to use it near aquaculture areas, rivers and ponds and other water bodies. It is prohibited to wash the application equipment in rivers and ponds and other water bodies; the product of this application has a high risk to trichogrammatids and is prohibited to be used in areas where natural enemies such as trichogrammatids are released; used packaging should be properly handled and cannot be discarded at will or used for other purposes; pregnant women and breastfeeding women are prohibited from contacting this product.

[0080] (5) If the product of this application is accidentally ingested, symptoms of poisoning such as dizziness, nausea, and vomiting may occur. Please seek medical assistance immediately. Do not induce vomiting and treat the symptoms. The product of this application is irritating to the skin and eyes. Avoid direct contact with the liquid during operation. If it splashes into the eyes, rinse them immediately with clean water for at least 15 minutes and then seek medical treatment. If it comes into contact with the skin, take off the contaminated clothes as soon as possible and wash them repeatedly with clean water and soap.

[0081] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A carbendazim wettable powder, characterized in that: The components include the following mass percentages: 45-50wt% carbendazim, 0.5-2wt% wetting agent, 3-10wt% auxiliary dispersant a, 3-10wt% auxiliary dispersant b, and the balance is filler; Wherein, the auxiliary dispersant a is sodium polycarboxylate, and the auxiliary dispersant b is a modified lignin-based dispersant, and the preparation steps are as follows: S1. Mix the pulping black liquor and the oxidant, and react at 60-75°C for 1-1.5h to obtain liquid A; S2. Add any one of formaldehyde, acetaldehyde, urea or acrylic acid to the solution A obtained in S1, and add 1 part by mass of formaldehyde, acetaldehyde, urea or acrylic acid to every 40 to 60 parts by mass of solution A; adjust the pH value to 9 to 11, and react at a temperature of 60 to 90° C. for 2 to 3 hours to obtain solution B; S3. Add a sulfonating agent to the liquid B obtained in S2, adjust the pH value to 4-6, react at 70-95°C for 2.5-4h, then let stand to room temperature, dry, grind and sieve to obtain an auxiliary dispersant b; The wetting agent is sodium dodecylbenzene sulfonate; S1: the pulping black liquor is prepared from any one or more of bamboo, wood or straw by an alkali method, the oxidant is any one of hydrogen peroxide, potassium permanganate, potassium dichromate or potassium iodate, and the mass ratio of the pulping black liquor to the oxidant is (60-70):1; The sulfonating agent in S3 includes any one of sulfite, aminosulfonic acid or chlorosulfonic acid, and the mass ratio of the B liquid to the sulfonating agent is (30-50):

1.

2. A carbendazim wettable powder according to claim 1, characterized in that, The filler is any one or more of diatomaceous earth, kaolin, white carbon black, talcum powder, montmorillonite and corn starch.

3. The method for preparing a carbendazim wettable powder according to claim 1 or 2, characterized in that: Weigh carbendazim, wetting agent, auxiliary dispersant a, auxiliary dispersant b and filler according to weight percentage, mix evenly and sieve to obtain carbendazim wettable powder.

4. The use of a carbendazim wettable powder according to claim 1 or 2, characterized in that: Used for the prevention and treatment of vegetable sclerotinia disease.

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