Method for producing ADC foaming agent by using chlorine gas-oxidized HDCA (biurea) in saturated hydrochloric acid solution

A technology of ADC foaming agent and hydrochloric acid solution, which is applied in the field of chlorine gas oxidation of HDCA to produce ADC foaming agent, can solve the problems of unutilized, unclean washing, and unstable product quality, so as to save resources, realize recycling, improve The effect of reaction rate

Active Publication Date: 2012-09-19
HANGZHOU HI TECH FINE CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the chlorine oxidation method cannot be used because dilute hydrochloric acid is produced in the reaction, and some inorganic salts are entrained. The follow-up ADC foaming agent washing process is not clean, resulting in unstable product quality.

Method used

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  • Method for producing ADC foaming agent by using chlorine gas-oxidized HDCA (biurea) in saturated hydrochloric acid solution
  • Method for producing ADC foaming agent by using chlorine gas-oxidized HDCA (biurea) in saturated hydrochloric acid solution

Examples

Experimental program
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Effect test

Embodiment 1

[0025] Weigh 100g of biurea and 30g of water in a 1L reaction kettle, and weigh 30g of saturated hydrochloric acid solution in the reaction kettle, turn on the stirring paddle and stir to make the slurry evenly stirred. Weigh 3gNaBr in the reactor, adjust the reaction temperature to 25°C, open the pipeline for chlorine gas, feed chlorine gas at a rate of 0.1mol / h, and produce hydrazine hydrochloride through the pipeline at the gas outlet into the reactor of hydrazine hydrate. After the reaction, the product ADCA was filtered, washed and dried, and the yield after weighing was 92%, and the reaction rate of hydrazine hydrochloride could be doubled.

Embodiment 2

[0027] Weigh 100g of biurea and 30g of water in a 1L reaction kettle, and weigh 30g of saturated hydrochloric acid solution in the reaction kettle, turn on the stirring paddle and stir to make the slurry evenly stirred. Weigh 5g of NaBr in the reaction kettle, adjust the reaction temperature to 50°C, open the pipeline for chlorine gas, and feed chlorine gas at a rate of 0.3mol / h, and the pipeline at the gas outlet is connected to the reactor of hydrazine hydrate to produce hydrazine hydrochloride. After the end, the product ADCA is filtered, washed and dried, and the yield after weighing is 95%, and the reaction rate of hydrazine hydrochloride can be doubled.

Embodiment 3

[0029] Weigh 100g of biurea and 30g of water in a 1L reaction kettle, and weigh 30g of saturated hydrochloric acid solution in the reaction kettle, turn on the stirring paddle and stir to make the slurry evenly stirred. Weigh 8gNaBr in the reactor, adjust the reaction temperature to 75°C, open the pipeline for chlorine gas, feed chlorine gas at a rate of 0.5mol / h, and produce hydrazine hydrochloride through the pipeline at the gas outlet into the reactor of hydrazine hydrate. After the reaction, the product ADCA was filtered, washed and dried, and the yield was 98% after weighing, and the reaction rate of hydrazine hydrochloride could be doubled.

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Abstract

The invention relates to a method for producing an ADC foaming agent by using chlorine gas-oxidized HDCA (biurea) in a saturated hydrochloric acid solution. The method comprises the following steps of: weighing a certain mass of HDCA, water and saturated hydrochloric acid solution in the mass ratio of 3:1:1, putting into a reaction kettle, and stirring uniformly to obtain slurry; weighing sodium bromide of which the amount is 3-8 percent by mass of the HDCA, adding into the reaction kettle, and connecting a chlorine gas pipeline to the reaction kettle; adding chorine gas at the flow of 0.1-0.5mol/h for oxidizing, wherein chlorine hydride gas overflows continuously in a reacting process; and controlling the reaction temperature at 25-75 DEG C till reacting completely. The method has the beneficial effects: ADCA (Azodicarbonamide) is provided by using chlorine gas-oxidized HDCA in the saturated hydrochloric acid solution, so that the defect of incapability of utilizing dilute hydrochloric acid serving as a byproduct in the conventional process can be avoided. A chlorinated hydrazine is produced by using chlorine hydride gas serving as a byproduct and a hydrazine hydrate, so that the reaction rate can be increased, and resources are saved. According to the method, circular utilization of all raw materials and side products can be realized.

Description

technical field [0001] The invention relates to the field of foaming agents, and mainly relates to a method for producing ADC foaming agent by oxidizing HDCA with chlorine gas in a saturated hydrochloric acid solution. Background technique [0002] The scientific name of ADC foaming agent is azodicarbonamide, and its molecular formula is: H 2 NC(O)N=NC(O)NH 2 , is a non-toxic foaming agent with excellent performance, widely used in the processing of foamed products such as plastics and rubber, and can also be used as an additive in certain foods. [0003] ADC blowing agent consists of biurea (H 2 NC(O)N(H)-N(H)C(O)NH 2 It is produced by oxidation, and there are many oxidation methods. At present, chlorine oxidation, hydrogen peroxide oxidation, and sodium chlorate oxidation are widely used. Among them, chlorine oxidation is more common in China because of the abundant sources of chlorine. Chlorine balance plays a role in regulation. However, due to the dilute hydrochlor...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C281/20
Inventor 董梅陈海贤
Owner HANGZHOU HI TECH FINE CHEM
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