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CN-122010805-A - Homogeneous zinc complexing process of mancozeb

CN122010805ACN 122010805 ACN122010805 ACN 122010805ACN-122010805-A

Abstract

The invention discloses a homogeneous zinc complexing process of mancozeb, and belongs to the technical field of pesticide chemical industry. The invention adds mancozeb and aprotic polar solvent or ionic liquid into a reaction kettle, heats to 70-120 ℃, continuously adds zinc salt, stirs and reacts for 50-150 min, filters after the reaction is finished, and dries the solid to obtain the mancozeb in a complete complex state. The method has the advantages of high process stability, low cost, good repeatability, high mancozeb content and high yield, is safe to crops, environment-friendly and harmless to people and livestock, and achieves the production purposes of safety, high quality, high efficiency, economy and environment friendliness.

Inventors

  • YUAN HAIYONG
  • TANG LIXIN
  • WU CHENGLONG

Assignees

  • 江西大如生物有限公司

Dates

Publication Date
20260512
Application Date
20260121

Claims (10)

  1. 1. The homogeneous zinc complexing process of mancozeb is characterized by comprising the following steps of: Firstly, adding mancozeb and a solvent into a reaction kettle, heating to 70-120 ℃, and continuously adding zinc salt to react by stirring for 50-150 min; the solvent is aprotic polar solvent or ionic liquid; and step two, filtering after the reaction is finished, and drying the solid to obtain the completely-complexed mancozeb.
  2. 2. The homogeneous zinc complexing process of mancozeb according to claim 1, wherein the preparation method of mancozeb in step one is characterized in that a dispersing agent is added into an aqueous solution of mancozeb, stirring and clearing are carried out, the temperature is raised to 40-60 ℃, an aqueous solution of manganese sulfate is dropwise added, the dropwise adding time is controlled to 40-60 min, the temperature is kept at 50-60 ℃ for 1-2 h after the dropwise adding is finished, and the mancozeb is obtained through filtration.
  3. 3. The homogeneous zinc complexing process of mancozeb according to claim 2, wherein the dispersing agent is calcium lignosulfonate, sodium calcium lignosulfonate or sodium dibutyl naphthalene sulfonate.
  4. 4. The homogeneous zinc complexing process of mancozeb according to claim 2, wherein the manganese sulfate aqueous solution is prepared by mixing manganese sulfate monohydrate and water according to a mass ratio of 1.38:3, and the amount of the dropwise added manganese sulfate aqueous solution is 1 (1-1.1) according to the molar ratio of mancozeb to manganese sulfate.
  5. 5. The homogeneous zinc complexing process of mancozeb according to claim 2 is characterized in that the preparation method of the mancozeb aqueous solution comprises the steps of adding ethylenediamine into ammonia water, slowly dripping carbon disulfide, carrying out heat preservation reaction after dripping, standing and separating liquid after the system becomes clear orange-yellow solution, and separating the carbon disulfide to obtain the mancozeb aqueous solution.
  6. 6. The homogeneous zinc complexing process of mancozeb according to claim 1, wherein in step one the zinc salt is at least one of zinc nitrate, zinc sulfate, zinc chloride, zinc acetate and hydrates thereof.
  7. 7. The homogeneous zinc complexing process of mancozeb according to claim 1, wherein the solvent in the first step is at least one of pyridine, acetonitrile, sulfolane, tetrahydrofuran, dimethylformamide, dimethyl sulfoxide, isosorbide dimethyl ether, hexamethylphosphoric triamide, N-methylpyrrolidone, quaternary ammonium salt ionic liquid and imidazole ionic liquid.
  8. 8. The homogeneous zinc complexing process for mancozeb according to claim 1, wherein in the first step, the molar ratio of mancozeb to zinc salt is 1:1.
  9. 9. The homogeneous zinc complexing process for mancozeb according to claim 1, wherein the mass ratio of mancozeb to solvent in the first step is 1 (1-12).
  10. 10. The homogeneous zinc complexing process for mancozeb according to claim 1, wherein the drying condition of the solid in the second step is vacuum drying at 80 ℃.

Description

Homogeneous zinc complexing process of mancozeb Technical Field The invention belongs to the technical field of pesticide chemical industry, and particularly relates to a homogeneous zinc complexing process of mancozeb. Background The mancozeb is an excellent protective bactericide, has the characteristics of high efficiency, low toxicity, broad spectrum, slow resistance development and the like, can prevent and treat epidemic diseases of various fruit trees and vegetables, such as downy mildew, powdery mildew, anthracnose and other fungal diseases, and has special effects on citrus black spot. The chemical name of mancozeb is ethylene bis-dithiocarbamic acid manganese zinc complex, which is a surface complex formed by zinc ions and the surface of mancozeb particles, and due to technical limitations, the local chemical reaction of the zinc ions and the surface of mancozeb particles in most of the current processes can only obtain non-full complex products with different degrees. The mancozeb in a non-fully-complex state has low content and poor stability, and the mancozeb which is not complexed in the use process rapidly releases excessive manganese ions, so that the mancozeb has great phytotoxicity to crops and can cause indirect injury to people and animals. Therefore, it is extremely important to produce mancozeb in a completely complexed state. At present, the zincification process of mancozeb mainly comprises a grinding zincification method and an azeotropic dehydration zincification method, wherein the grinding zincification method reduces the particle size of mancozeb (5-15 mu m) through physical grinding, increases the reaction contact area, promotes the complexation reaction and improves the complexation degree of mancozeb and zinc ions, but the grinding zincification method has long grinding time, serious equipment abrasion and huge process energy consumption. The azeotropic dehydration zinc complexing method is a heterogeneous zinc complexing process by azeotropic dehydration in the presence of an organic solvent which can azeotropy with water and simultaneously complexing manganese and zinc, and the obtained mancozeb is not in a complete complexing state, so that the problems of phytotoxicity and poor stability still exist. In view of the above, it is important to research a production process of completely complex mancozeb with high quality, stability and low cost. Disclosure of Invention Aiming at the background technology, the invention aims to provide a homogeneous zinc complexing process of mancozeb, which is used for producing the mancozeb in a complete complexing state, so as to solve the problems of low mancozeb content, high process cost, poor stability, phytotoxicity to crops and indirect injury to people and livestock in the prior art, and realize the production aims of safety, high quality, high efficiency, economy and environmental friendliness. In order to achieve the above purpose, the present invention adopts the following technical scheme: the invention provides a homogeneous zinc complexing process of mancozeb, which comprises the following steps: Firstly, adding mancozeb and a solvent into a reaction kettle, heating to 70-120 ℃, and continuously adding zinc salt to react by stirring for 50-150 min; the solvent is aprotic polar solvent or ionic liquid; and step two, filtering after the reaction is finished, and drying the solid to obtain the completely-complexed mancozeb. As a preferred implementation mode, the preparation method of the mancozeb in the step one comprises the steps of adding a dispersing agent into a mancozeb aqueous solution, stirring and dissolving, heating to 40-60 ℃, dropwise adding a manganese sulfate aqueous solution, controlling the dropwise adding time to 40-60 min, keeping the temperature at 50-60 ℃ after the dropwise adding is finished for 1-2 h, and filtering to obtain the mancozeb. As a preferred embodiment, the dispersing agent is calcium lignosulfonate, sodium calcium lignosulfonate, or sodium dibutyl naphthalene sulfonate. As a preferable implementation mode, the manganese sulfate aqueous solution is prepared by mixing manganese sulfate monohydrate and water according to a mass ratio of 1.38:3, and the amount of the manganese sulfate aqueous solution added dropwise is 1 (1-1.1) according to the mole ratio of the ambam to the manganese sulfate. As a preferred embodiment, the preparation method of the ambam aqueous solution comprises the steps of adding ethylenediamine into ammonia water, slowly dripping carbon disulfide, carrying out heat preservation reaction after dripping, standing and separating liquid after the system becomes a clear orange-yellow solution, and separating the carbon disulfide to obtain the ambam aqueous solution. In a preferred embodiment, the zinc salt in the step one is at least one of zinc nitrate, zinc sulfate, zinc chloride, zinc acetate and hydrates thereof. In a preferred embodiment, the solvent in the first step is at