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CN-121975104-A - Polyether for pesticide suspending agent and preparation method thereof

CN121975104ACN 121975104 ACN121975104 ACN 121975104ACN-121975104-A

Abstract

The invention belongs to the technical field of pesticide assistants, and particularly relates to polyether for a pesticide suspending agent and a preparation method thereof. The preparation method comprises the following steps of (1) taking aromatic diamine as an initiator, dewatering, starting to dropwise add propylene oxide for reaction, aging after the dropwise adding is finished to generate an intermediate aromatic diamine polyoxypropylene ether, (2) taking the intermediate aromatic diamine polyoxypropylene ether as an initiator, taking potassium hydroxide as a catalyst, dewatering, starting to dropwise add propylene oxide for reaction, aging after the dropwise adding is finished, and (3) dropwise add ethylene oxide for reaction, aging after the dropwise adding is finished, and performing aftertreatment to obtain polyether for the pesticide suspending agent. The polyether can be adsorbed on the surfaces of various pesticide particles to form a thick and stable hydration layer, so that the steric hindrance stability is improved, and meanwhile, the polyether has good temperature resistance, and keeps stable structure and durable function in long-term storage, so that the physical stability, adaptability and shelf life of the pesticide suspending agent are fundamentally improved.

Inventors

  • LU CHEN
  • CHEN JI
  • HE ZHIQIANG
  • ZHANG KAI

Assignees

  • 上海东大化学有限公司

Dates

Publication Date
20260505
Application Date
20260114

Claims (10)

  1. 1. A preparation method of polyether for pesticide suspending agent is characterized by comprising the following steps: (1) Taking aromatic diamine as an initiator, dewatering, then starting to dropwise add propylene oxide for reaction, and aging after the dropwise adding is finished to generate an intermediate aromatic diamine polyoxypropylene ether; (2) Taking an intermediate aromatic diamine polyoxypropylene ether as an initiator, taking potassium hydroxide as a catalyst, dewatering, starting to dropwise add propylene oxide for reaction, and aging after the dropwise addition is finished; (3) Dripping ethylene oxide for reaction, aging after dripping, and performing post-treatment to obtain polyether for pesticide suspending agent; the polyether for the pesticide suspending agent has the structural formula as follows: , Wherein, R is benzene, naphthalene or diphenyl methane aromatic group, m1, m2, m3, m4=13-18, n1, n2, n3, n4=14-19.
  2. 2. The method according to claim 1, wherein in the step (1), the aromatic diamine is one or more of p-xylylenediamine, 4' -diaminodiphenylmethane and 1, 4-diaminonaphthalene.
  3. 3. The method for preparing polyether for pesticide suspending agent according to claim 1, wherein in the step (1), the reaction temperature is 150-165 ℃, and the aging temperature is 150-165 ℃.
  4. 4. The method for preparing polyether for pesticide suspending agent according to claim 1, wherein in the step (1), the intermediate aromatic diamine polyoxypropylene ether has the following structural formula: , wherein R is benzene, naphthalene or diphenyl methane aromatic group.
  5. 5. The method of claim 1, wherein in the step (2), the amount of potassium hydroxide is 0.2 to 0.5% by mass of the total mass of the intermediate aromatic diamine polyoxypropylene ether in the step (2), potassium hydroxide, propylene oxide and ethylene oxide in the step (3).
  6. 6. The method of claim 1, wherein in the step (2), the reaction temperature is 105-125 ℃, and the aging temperature is 105-125 ℃.
  7. 7. The method for preparing polyether for pesticide suspending agent according to claim 1, wherein in the step (3), the reaction temperature is 140-160 ℃, and the aging temperature is 140-160 ℃.
  8. 8. The method for preparing polyether for pesticide suspending agent according to claim 1, wherein in the step (3), the post-treatment is degassing and neutralization, and the neutralization is carried out until the pH is 6-8.
  9. 9. The method for preparing polyether for pesticide suspending agent according to claim 1, wherein in the step (3), the ethylene oxide chain segment accounts for 45-50% of the molecular weight of the ethylene oxide and propylene oxide chain segments.
  10. 10. A polyether for a pesticide suspension, characterized in that the polyether for a pesticide suspension is prepared by the preparation method of the polyether for a pesticide suspension according to any one of claims 1 to 9.

Description

Polyether for pesticide suspending agent and preparation method thereof Technical Field The invention belongs to the technical field of pesticide assistants, and particularly relates to polyether for a pesticide suspending agent and a preparation method thereof. Background The pesticide suspending agent is used as an environment-friendly and efficient water-based preparation, and has become an important direction for the development of pesticide preparations. The pesticide is formed by stably dispersing a solid pesticide raw material insoluble in water in the form of tiny particles by means of a surfactant and other auxiliary agents. The preparation has the advantages of no organic solvent, environmental friendliness, safe use, high drug effect and the like. However, the physical stability of suspending agents (e.g., anti-settling, anti-flocculation, anti-crystal growth, and anti-oshi ripening) is a key technical bottleneck that limits their product quality and shelf life. In the formulation of suspending agents, surfactants, particularly dispersants and wetting agents, play a decisive role in maintaining a stable dispersion of particles. Polyether surfactants such as alkylphenol ethoxylates, fatty alcohol ethoxylates and block polyethers (e.g., ethylene oxide-propylene oxide copolymers) are widely used in pesticide suspending agents because of their excellent wetting, dispersing and steric hindrance effects. They are adsorbed on the surface of pesticide particles to form hydrophilic polymer layer to provide electrostatic repulsion and steric hindrance to prevent mutual approaching and coalescence between particles. However, polyether dispersants commonly used in the prior art still have several limitations: (1) The structural universality is insufficient, the molecular structure of the traditional polyether is relatively single, and the hydrophilic-lipophilic balance (HLB) and the molecular chain segment arrangement mode are fixed. The adsorption adaptability and the steric hindrance effect of the pesticide are obvious for pesticide raw materials with different polarities, different crystal forms and different particle diameters. Polyether often only shows excellent dispersing effect on specific types of raw medicines, lacks broad-spectrum suitability, and needs to frequently screen and compound a plurality of surfactants in formula development, so that the process is tedious and the cost is increased. (2) The suspending agent is easy to separate out or lose efficacy after long-term storage, the temperature is periodically changed to change the hydrophilic/lipophilic balance of the polyether chain, when the temperature is lower, polyether can be desorbed from the particle surface and dispersed in water, when the temperature is higher, the polyether molecular chain can curl on the particle surface, so that the particles lose effective steric hindrance protection, the suspending agent is creamed, bottom-adhered or particle size is increased, and the like, and the shelf life and the use effect of the preparation are seriously influenced. Therefore, there is a need in the art to develop a polyether having strong structural versatility and good temperature resistance. Disclosure of Invention The polyether prepared by the method can be adsorbed on the surfaces of various pesticide particles strongly to form a thick and stable hydration layer, so that the steric stability is improved, meanwhile, the polyether has good temperature resistance, and keeps stable structure and durable function in long-term storage, thereby fundamentally improving the physical stability, adaptability and shelf life of the pesticide suspending agent and simplifying the formula process. In order to achieve the above object, the present application provides the following technical solutions: the preparation method of the polyether for the pesticide suspending agent comprises the following steps: (1) Taking aromatic diamine as an initiator, dewatering, then starting to dropwise add Propylene Oxide (PO) for reaction, and aging after the dropwise adding is finished to generate an intermediate aromatic diamine polyoxypropylene ether; (2) Taking an intermediate aromatic diamine polyoxypropylene ether as an initiator, taking potassium hydroxide as a catalyst, dewatering, starting to dropwise add propylene oxide for reaction, and aging after the dropwise addition is finished; (3) Dripping Ethylene Oxide (EO) for reaction, aging after dripping, and performing post-treatment to obtain polyether for pesticide suspending agent; the polyether for the pesticide suspending agent has the structural formula as follows: , Wherein, R is benzene, naphthalene or diphenyl methane aromatic group, m1, m2, m3, m4=13-18, n1, n2, n3, n4=14-19. Compared with the traditional Pluronic block polyether, the polyether with the structure can more effectively prevent the unstable phenomenon of sedimentation caused by the increase of the grain diameter of pesticide particl