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Method for preparing high-purity resorcinol through melt crystallization

A technology of pure resorcinol and resorcinol, applied in chemical instruments and methods, preparation of organic compounds, organic chemistry, etc., can solve the problems of affecting product quality, difficulty in industrial production, low refining yield, etc. The effect of improving the working environment, protecting the health of employees, and high product purity

Active Publication Date: 2012-05-23
ZHEJIANG HONGSHENG CHEM IND +2
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0010] The solution crystallization method requires the use of organic solvents or water. In the solution crystallization process, in addition to the crystallization operation unit, operation units such as centrifugation, drying and solvent recovery are also required. The production process is long, and there are low refining yields, solvent loss, energy High consumption, waste water discharge, back-mixing of impurities entrained in the solvent, etc., and if the solvent components are not separated thoroughly, it will also affect the quality of the product and bring difficulties to industrial production

Method used

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  • Method for preparing high-purity resorcinol through melt crystallization
  • Method for preparing high-purity resorcinol through melt crystallization
  • Method for preparing high-purity resorcinol through melt crystallization

Examples

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Effect test

Embodiment 1

[0044] Prepare hydrolyzate with m-phenylenediamine, sulfuric acid, and water. The molar ratio of m-phenylenediamine, sulfuric acid, and water is 1:2.0:80. The temperature of the hydrolyzed liquid is 220-240°C. The reaction residence time is 3-6 hours. Cool down to normal temperature, extract with organic solvent butyl acetate, recover butyl acetate, water and low boilers from the extract by distillation, and remove the crude resorcinol from low boilers at 15~50mmHg, 160~190℃ Pressure rectification to remove high boiling impurities, the purity of crude resorcinol reaches 99.0-99.7%. The resorcinol melt condensed to ~122°C is used as the raw material for subsequent crystallization and refining, and is discharged into the raw material storage tank T2 for standby. see process figure 1 .

[0045] The falling film crystallizer used is composed of 3 vertical stainless steel tubes with a jacket, and the lower part is equipped with a liquid storage tank. The crystallizer, storage tan...

Embodiment 2

[0059] According to the method of Example 1, get 99.2% of the crude product resorcinol obtained by rectification and follow the same three-stage crystallization process to refine the crude product resorcinol, and the process conditions are as follows:

[0060]

[0061] The purity of the product obtained by the third stage crystallization reaches 99.999%.

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Abstract

The invention provides a method for preparing high-purity resorcinol through melt crystallization. The method mainly comprises steps of melt crystallization, partial melting (sweating) and melting. According to the invention, a graded melt crystallization method is adopted, and the process is carried out in a falling film dynamic crystallization device, such that non-pure resorcinol is purified. The adopted grade number should satisfy a final purity expectation obtained with a high yield. At least one grade is adopted, and commonly several grades are adopted. The grade number varies from 1 to 4, such that a complete resorcinol product crystallization refining circulation is formed. The method is advantaged in that: no solvent is required by melt crystallization, such that the product is prevented from being polluted by exterior solvents or other materials. Especially, latent pollution to resorcinol caused by back-mixing of solution crystallization impurities and degradation reactions caused by high rectification temperature can be prevented, and the influence of waste water caused by solution crystallization to the environment can be avoided. The product yield is high, the product purity is high, and the production efficiency is high.

Description

(1) Technical field [0001] The purpose of the invention is to provide a kind of production method of high-purity resorcinol. (2) Background technology [0002] Resorcinol (Resorcinol), commonly known as Resorcinol, also known as 1,3-benzenediol, etc., is an important organic chemical raw material, widely used in rubber, pesticides, dyes, paints, medicines, plastics, electronic chemicals and other fields, such as adhesives for tire cords, adhesive resins for synthetic rubber, high-performance adhesives for wood plywood, synthetic benzophenone-based ultraviolet absorbers, m-aminophenol, etc. China's resorcinol is mainly used to prepare the raw materials for the m-formula-white adhesive system required by the tire rubber industry. The quality requirements for resorcinol in this field are relatively high. In order to avoid the adverse effects of impurities in the product on the application , the purity of the product resorcinol generally reaches above 99.9%, and there are restr...

Claims

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Application Information

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IPC IPC(8): C07C39/08C07C37/84
Inventor 何旭斌陶建国张桂香王新武贡晗杨日升
Owner ZHEJIANG HONGSHENG CHEM IND
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