Search

CN-122010749-A - Method for purifying 3,3' -diaminobenzidine crude product and application thereof

CN122010749ACN 122010749 ACN122010749 ACN 122010749ACN-122010749-A

Abstract

The invention relates to the technical field of chemical engineering separation, and discloses a method for purifying a 3,3 '-diaminobenzidine crude product and application thereof, wherein the method comprises the following steps of (1) carrying out first mixing on the 3,3' -diaminobenzidine crude product and a good solvent to obtain a solution containing 3,3 '-diaminobenzidine; the good solvent comprises organic matters containing nitrogen elements and/or organic matters containing sulfur elements, the solution containing 3,3' -diaminobenzidine is mixed with a solvent for the second time, the solvent comprises water and/or monohydric alcohol, the product obtained by the second time is aged, the product obtained by the aging is subjected to second solid-liquid separation, and the solid obtained by the second solid-liquid separation is washed and dried. The method has the advantages of mild conditions, no need of nitrogen protection, small solvent consumption, and high-purity and high-yield 3,3' -diaminobenzidine product can be obtained by one-step crystallization.

Inventors

  • HAO HONGXUN
  • LI JI
  • ZHAO JIAWEI
  • WANG AILIAN
  • LI JING
  • WU JIANING
  • WANG TING
  • WANG NA
  • ZHANG LONGGUI
  • HE WEN

Assignees

  • 中国石油化工股份有限公司
  • 中石化(北京)化工研究院有限公司

Dates

Publication Date
20260512
Application Date
20241111

Claims (11)

  1. 1. A method for purifying a crude product of 3,3' -diaminobenzidine, which is characterized by comprising the following steps: (1) First mixing the 3,3 '-diaminobenzidine crude product with a good solvent to obtain a solution containing 3,3' -diaminobenzidine, wherein the good solvent comprises an organic matter containing nitrogen elements and/or an organic matter containing sulfur elements; (2) Second mixing a solution containing 3,3' -diaminobenzidine with a solvent, wherein the solvent comprises water and/or monohydric alcohol; (3) Aging the product obtained by the second mixing, performing the second solid-liquid separation on the aged product, and washing and drying the solid obtained by the second solid-liquid separation.
  2. 2. The process of claim 1, wherein the crude 3,3' -diaminobenzidine has a purity of 95-97%; And/or the good solvent comprises at least one of nitrobenzene, pyridine, N-dimethylformamide, N-dimethylacetamide, dimethyl sulfoxide and sulfolane; And/or, the amount of the good solvent used is 10 to 35mL per 10g of crude 3,3' -diaminobenzidine.
  3. 3. The method of claim 1, wherein the temperature of the first mixing is 5-30 ℃.
  4. 4. The process of claim 1 wherein step (2) further comprises contacting the solution comprising 3,3' -diaminobenzidine with activated carbon prior to the second mixing with the eluent, then subjecting the product of the contacting to a first solid-liquid separation, and then second mixing the solution obtained from the first solid-liquid separation with the eluent.
  5. 5. The process according to claim 4, wherein the amount of the activated carbon is 0 to 10g per 100g of the crude 3,3' -diaminobenzidine; and/or the contacting conditions comprise a temperature of 5-30 ℃ and a time of 0.5-1h.
  6. 6. The method of claim 1, wherein the elution agent is a C1-C5 monohydric alcohol and/or water, preferably at least one of methanol, ethanol, water, isopropanol and n-propanol; And/or the volume ratio of the solvent to the good solvent is 1-5:1; And/or, the solvent is mixed with the solution containing 3,3 '-diaminobenzidine in a dropwise manner, preferably at a rate of 100 to 300. Mu.L/min per 10g of crude 3,3' -diaminobenzidine.
  7. 7. The method of claim 1, wherein the second mixing is at a temperature of 5-30 ℃.
  8. 8. The method of claim 1, wherein the aging conditions comprise a temperature of 5-30 ℃ and a time of 0.5-2 hours.
  9. 9. The method according to claim 1, wherein the washing employs a detergent that is a C1-C5 monohydric alcohol and/or water, preferably at least one of methanol, ethanol, water, isopropanol and n-propanol.
  10. 10. The method of claim 1, wherein the drying conditions include a temperature of 40-60 ℃ for 3-8 hours under vacuum.
  11. 11. Use of the method according to any one of claims 1 to 10 for improving the uniformity of the particle size distribution of 3,3 '-diaminobenzidine crystals and/or for preparing 3,3' -diaminobenzidine crystals having a bulk morphology.

Description

Method for purifying 3,3' -diaminobenzidine crude product and application thereof Technical Field The invention belongs to the technical field of chemical engineering separation, and particularly relates to a method for purifying a 3,3' -diaminobenzidine crude product and application thereof. Background 3,3'-Diaminobenzidine (3, 3' -Diaminobenzidine) is also known as 3,3', 4' -tetraminobiphenyl, 3', 4' -biphenyltetramine, DAB, of formula C 12H14N4, molecular weight 214.27, which is one of the analogues of benzidine, a flowering color or brown solid at ambient temperature. The structural formula is as follows: 3,3' -diaminobenzidine, an important monomer for synthesizing polymers, can be used for preparing high molecular resins and fibers having excellent properties. Meanwhile, 3' -diaminobenzidine has mutagenicity, so that nucleic acid, protein and the like can be chemically stained. As an analytical detection reagent, it is commonly used for spectrophotometry to determine selenium content. The purity of the 3,3' -diaminobenzidine directly influences the accuracy of analysis and detection and the value and performance of subsequent synthesized products, so that the production scale of the 3,3' -diaminobenzidine is improved, and the 3,3' -diaminobenzidine is refined by developing and optimizing a crystallization process, thereby having important practical significance and wide development prospect. CN117756640A synthesizes 3,3 '-diaminobenzidine by adopting a two-step heating method, hot melting and cooling are carried out in hot water at 95-100 ℃ to obtain a3, 3' -diaminobenzidine crude product, water which is 40-50 times of the mass of the crude product and active carbon and antioxidant ammonium sulfate hydrochloride with the mass ratio of 1:1 are added into the crude product, and the 3,3 '-diaminobenzidine is obtained after dissolution, filtration and cooling at 97-103 ℃, and the high-purity 3,3' -diaminobenzidine is obtained by repeated purification operation for many times. The method has high operating temperature, needs nitrogen protection in the whole process, needs adding antioxidant, has large solvent consumption, and needs multiple purification to obtain the high-purity 3,3' -diaminobenzidine, so the total yield is not high. US3943175 adds acid to form salt, neutralizes the base, dissolves and cools the 3,3' -diaminobenzidine crude product with boiling water to obtain the 3,3' -diaminobenzidine solid product, which needs to consume a large amount of acid and base, consumes a large amount of solvent, has high operation temperature, and has low purity of the 3,3' -diaminobenzidine product. The 3,3 '-diaminobenzidine product is obtained by adding flocculant in US3481984, and crystallizing 120-125 ℃ 3,3' -diaminobenzidine aqueous solution through an activated carbon column, and the method has high cost and low efficiency. EP0522577B1 still requires a large amount of water as solvent in the process of purifying crude 3,3' -diaminobenzidine, and the dissolution temperature is above 100 ℃. In summary, the purification of 3,3' -diaminobenzidine has the problems of large wastewater amount, high operation temperature, high energy consumption, multiple crystallization, low yield and purity, high cost and the like. Disclosure of Invention The invention aims to overcome the problems in the prior art and provide a method for purifying a 3,3' -diaminobenzidine crude product and an application thereof, wherein the method adopts a solvent-out crystallization method, and the 3,3' -diaminobenzidine crude product is purified by using a specific good solvent and a specific solvent-out agent, so that the method has the advantages of mild condition, no need of nitrogen protection, small solvent consumption and large single-batch processing capacity, and the 3,3' -diaminobenzidine product with high purity and high yield can be obtained by only one-step crystallization. In order to achieve the above object, the first aspect of the present invention provides a method for purifying a crude 3,3' -diaminobenzidine, comprising the steps of: (1) First mixing the 3,3 '-diaminobenzidine crude product with a good solvent to obtain a solution containing 3,3' -diaminobenzidine, wherein the good solvent comprises an organic matter containing nitrogen elements and/or an organic matter containing sulfur elements; (2) Second mixing a solution containing 3,3' -diaminobenzidine with a solvent, wherein the solvent comprises water and/or monohydric alcohol; (3) Aging the product obtained by the second mixing, performing the second solid-liquid separation on the aged product, and washing and drying the solid obtained by the second solid-liquid separation. In a second aspect, the invention provides the use of the method described above for improving the uniformity of the particle size distribution of 3,3 '-diaminobenzidine crystals and/or for preparing 3,3' -diaminobenzidine crystals having a bulk morphology. Through the technical scheme, the