Method of semi-continuously producing particle-size-controllable ADC (azodicarbonamide) foaming agent

A semi-continuous technology for ADC foaming agent, applied in the field of semi-continuous production of ADC foaming agent with controllable particle size, to achieve the effect of reducing post-processing procedures, improving product quality stability, and improving use stability

Active Publication Date: 2013-04-03
HANGZHOU HI TECH FINE CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] At present, the industrial production of ADC foaming agent generally adopts single-tank reaction. Each kettle needs to complete the process of feeding, reacting, discharging, washing the kettle, and feeding. When reacting in the kettle, the lid kettle is used as a separate reaction unit. , the particle size of...

Method used

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  • Method of semi-continuously producing particle-size-controllable ADC (azodicarbonamide) foaming agent
  • Method of semi-continuously producing particle-size-controllable ADC (azodicarbonamide) foaming agent

Examples

Experimental program
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Effect test

Embodiment 1

[0026] The continuous reactor volume R01 is 300L, and the batch reactor R02 is 10L. Biurea is formulated into a slurry with a solid content of 30%. First consider oxidation with hydrogen peroxide, and then add hydrochloric acid, sodium bromide, and an iron-based catalyst to make the content of hydrochloric acid in the slurry 8%, and the content of sodium bromide 1%. The content of iron-based catalyst is 0.6%, and the total amount of biurea slurry after preparation is 400L. Then feed into the continuous reactor R01, start stirring, control the stirring speed at 20 rpm (frequency 15hz), stop feeding when the slurry level is just ready for forced circulation, open the hydrogen peroxide feed valve, and start the continuous reaction Add 40% industrial hydrogen peroxide to the reactor at a rate of 1L / h to react, turn on the refrigerant, control the material temperature of the continuous reactor to 50°C, and take a sample at the material outlet after reacting for 3 to 5 hours, and th...

Embodiment 2

[0029] The continuous reactor volume R01 is 300L, and the batch reactor R02 is 10L. Biurea is formulated into a slurry with a solid content of 30%, oxidized with hydrogen peroxide, and then adding hydrochloric acid, sodium bromide, and an iron-based catalyst to make the slurry have a hydrochloric acid content of 8%, a sodium bromide content of 1%, and an iron-based catalyst. The catalyst content is 0.6%, and the biurea slurry after preparation is 400L in total. Then feed the material to the continuous reactor R01, start stirring, control the stirring speed at 55 rpm (frequency 40hz), and when the slurry level is just ready for forced circulation, stop feeding, open the hydrogen peroxide feed valve, and feed to the continuous reactor R01. Add 40% industrial hydrogen peroxide to the reactor at a rate of 1L / h for reaction, turn on the refrigerant, control the temperature of the material in the continuous reactor to 50°C, and take a sample at the material outlet after reacting for...

Embodiment 3

[0032] The continuous reactor volume R01 is 300L, and the batch reactor R02 is 10L. The biurea is formulated into a slurry with a solid content of 30%, which is oxidized by chlorine gas. The content of sodium bromide in the slurry is 0.8% of the biurea content, and the total amount of the biurea slurry after preparation is 400L. Then feed the continuous reactor R01, start stirring, control the stirring speed to 42 rpm (frequency is 30hz), and when the slurry liquid level is just able to carry out forced circulation, stop feeding, open the chlorine gas feed valve, and start liquid Phase feed, add chlorine gas to the continuous reactor at a rate of 70L / h to react, turn on the refrigerant, control the material temperature of the continuous reactor to 35°C, and take a sample at the material outlet after reacting for 3 to 5 hours. When the amount reaches about 30%, open the biurea feed valve, feed the material into the continuous reactor R01 according to the speed of 10L / h, and adj...

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Abstract

The invention provides a method of semi-continuously producing a particle-size-controllable ADC (azodicarbonamide) foaming agent. Staged reactions are adopted, an oxidizing agent is continuously added, a reaction system is controlled in a certain acidity range, a first stage reaction is continuous, according to the characteristics that true specific gravities of biurea and ADC are the same and particular diameters of the two are different, the particle size of the ADC generated by the reaction is controlled through using a swirl rising liquid flow to perform hierarchical control; and a second stage reaction is a discontinuous reaction, and all reactions are guaranteed to reach endpoint, so that the product quality is guaranteed. The process has the advantages that when the ADC is generated by the reactions, the particle size of the ADC foaming agent can be controlled, and a later crushing process can be reduced, so that an original crystal state is not physically damaged, and meanwhile, the particle size of the product is narrow, and because most reactions are finished in the first stage, batch differences between single kettles are also greatly reduced, and the use stability of the ADC foaming agent is more in favor of being improved.

Description

technical field [0001] The invention relates to the field of foaming agents, in particular to a method for semi-continuously producing ADC foaming agents with controllable particle size. Background technique [0002] ADC foaming agent (azodicarbonamide) is the most widely used general-purpose foaming agent in foam products. It is widely used in Plastic products such as polyethylene, polyvinyl chloride, polystyrene, polypropylene, ABS resin and EVA, and rubber products. [0003] At present, the industrial production of ADC foaming agent generally adopts a single-pot reaction. Each pot needs to complete the process of feeding, reacting, discharging, washing the pot, and feeding. When reacting in the pot, the covered pot is used as a separate reaction unit. , the particle size of ADC is difficult to control. It can only roughly affect the particle size and distribution of ADC according to temperature and reaction speed. The particle size distribution is relatively wide, and th...

Claims

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Application Information

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IPC IPC(8): C07C281/20
Inventor 魏增陈海贤
Owner HANGZHOU HI TECH FINE CHEM
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