Preparation method of captan

A technology of captan and mixed solution, which is applied in the field of captan preparation, can solve the problems of large amount of waste water, poor environmental protection such as long-term storage and decomposition, and long heating and alkaline hydrolysis time, etc.

Active Publication Date: 2021-04-13
YINGDE GREATCHEM CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The inventive process promotes the decomposition of unreacted perchloromethanethiol by heating under alkaline conditions, which solves the technical problems of poor environmental protection such as strong irritating odor and long-term storage decomposition.
But in this method condensation reaction, 1,2,3,6-tetrahydrophthalimide and perchloromethanethiol have a longer reaction time in the tank reactor, and the crude product purification heating alkaline hydrolysis time is longer, As a result, there are more by-products, the content of finished products is not high, and all the filtrate is directly discharged after washing, and the amount of waste water is large. Therefore, there is still room for improvement

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0036] Embodiment 1, a kind of preparation method of Captan

[0037] A preparation method of captan, comprising the following steps:

[0038] S1. Add 90kg (683.3mol) of liquid caustic soda with a content of 30.11% and 400kg of water into a 1000L reactor; start stirring, and put in 1,2,3,6-tetrahydrophthalimide with a content of 98.3% 100kg (650.3mol) is mixed to form a mixed solution, stirred until all the materials are dissolved and cooled to 10°C, and then introduced into the tower reactor from the upper part at a flow rate of 1.0kg / s.

[0039] S2. Adding content is 98.5% perchloromethanethiol 125kg (662.3mol) in the head tank, then with the flow rate of 0.2kg / s, introduce tower reactor from the middle; Open the vent valve at the bottom of the tower reactor, first at 0.6Nm 3 The airflow per minute is fed into the compressed air from the bottom of the tower to make the materials in the reactor turbulently mix and generate foam; then gradually increase the airflow to 2.0Nm ...

Embodiment 2

[0043] Embodiment 2, a kind of preparation method of Captan

[0044] A preparation method of captan, comprising the following steps:

[0045] S1. Adding 90kg (684.4mol) of 30.42% liquid caustic soda and 380kg of rinsing filtrate and 80kg of fresh water (460kg in total) containing 0.33% sodium chloride into a 1000L reactor; start stirring, and input 98.58% 1, 100kg (652.2mol) of 2,3,6-tetrahydrophthalimide was stirred until the material was completely dissolved and cooled to 15°C, then introduced into the tower reactor from the upper part at a flow rate of 1.1kg / s.

[0046] S2. Add 97.02% perchloromethanethiol 130kg (678.5mol) in the high-level tank, then introduce the reactor from the middle at a flow rate of 0.2kg / s; 3 The air flow per minute is fed into the compressed air from the bottom of the tower to make the materials in the reactor turbulently mixed, and then gradually increase the air flow to 1.8Nm 3 / min, so that the reactor liquid flooded and mist overflowed; at th...

Embodiment 3

[0050] Embodiment 3, a kind of preparation method of Captan

[0051] A preparation method of captan, comprising the following steps:

[0052] S1. Add 90kg (681.9mol) of 30.31% liquid caustic soda and 400kg of rinsing filtrate containing 0.41% salt into a 1000L reactor, start stirring; put in 99.62% 1,2,3,6-tetrahydrophthalate 100 kg (659.1 mol) of dicarboximide was stirred until all the materials were dissolved and the temperature was lowered to 10°C, and then fed into the tower reactor from the top at a flow rate of 1.0 kg / s.

[0053] S2. Adding content is 99.26% perchloromethanethiol 125kg (667.5mol) in the head tank, then with the flow velocity of 0.2kg / s, introduce reactor from the middle, open the vent valve at the bottom of the reactor, with 0.6Nm 3 The airflow per minute is fed into the compressed air from the bottom of the tower to make the materials in the reactor turbulently mixed. Then increase the air flow to 1.7~1.8Nm 3 / min, so that the reactor liquid flooded ...

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PUM

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Abstract

The invention relates to the technical field of pesticide synthesis, and particularly discloses a preparation method of captan. The preparation method comprises the following steps: S1, dissolving 1, 2, 3, 6-tetrahydrophthalimide in an alkaline solution to form a mixed solution, and cooling the mixed solution; S2, carrying out condensation reaction on perchloromethyl mercaptan and the mixed solution cooled in the step S1 in a tower reactor, and introducing compressed air for bubbling to form flooding entrainment; and S3, separating the flooding entrainment from the mixed solution obtained in the step S2, and heating, filtering, washing and drying the mixed solution obtained after separation to obtain the captan. The process is simple, the generated impurities are low, the generated wastewater is less, the product yield is high, and the prepared captan is good in quality and high in purity.

Description

technical field [0001] The invention relates to the technical field of pesticide synthesis, in particular to a preparation method of captan. Background technique [0002] Captan, whose chemical name is N-trichloromethylthio-1,2,3,6-tetrahydrophthalimide, belongs to the traditional multi-site organosulfur fungicides. Mainly, it also has a certain therapeutic effect, and has a good control effect on various diseases of barley, wheat, oats, rice, corn, cotton, vegetables, fruit trees, melons, tobacco and other crops. It also has a good control effect on three wheat head blight, rice sheath blight, rice blast, wheat stem embroidery, tobacco red spot, cotton seedling disease, apple rot, etc. The fungicide does not contain metal ions, is safe for crops, is especially suitable for cabbage, cucumber and other crops that are sensitive to copper-based pesticides, and is non-toxic to bees. Captan can also stimulate plant growth, increase the thickness of the wax layer on the crop sur...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D209/48
CPCC07D209/48Y02A50/20
Inventor 雷进海王世银吴光辉张新波林有清谭永清黄卫荣
Owner YINGDE GREATCHEM CHEM
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