Method for refining p-phenylene diamine

A p-phenylenediamine and refining method technology, which is applied in the purification/separation of amino compounds, organic chemistry, etc., can solve the problems of crystallization that is difficult to reach an equilibrium state, molecular mobility hindrance, and adhesion to the crystal surface, etc., to reduce labor costs and maintenance costs, to protect the health of employees, the effect of low cost

Active Publication Date: 2008-08-27
上海鸿源鑫创材料科技有限公司 +2
View PDF1 Cites 24 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

During the cooling process of p-phenylenediamine, the molecular mobility is hindered, and it is difficult to form its own crystal nucleus. In order to ensure the production capacity of the crystallization device, it is usually difficult to reach an equilibrium state for crystallization, which is controlled by heat transfer, mass transfer

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method for refining p-phenylene diamine
  • Method for refining p-phenylene diamine

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0036] The product of catalytic hydrogenation of p-nitroaniline removes water and solvent, mixes with the mother liquor of the first-stage molten crystallization and enters the rectification tower, and removes low boiling substances and other front fractions through vacuum distillation at a vacuum degree of about 0.096MPa. The tower bottom liquid enters the second rectification tower, rectification steams p-phenylenediamine, condenses to obtain p-phenylenediamine with a purity of 99%, and puts it into No. (1) intermediate tank for subsequent crystallization and purification (flow process see figure 2 ); all crystallizers, storage tanks and pipelines used are sealed, and the original air is replaced with nitrogen.

[0037] In 3000L stainless steel shell and tube falling film crystallizer, storage tank and piping system (see figure 1 ): put the p-phenylenediamine condensate obtained from the rectification of No. (1) intermediate tank, the second-stage sweating liquid of the pri...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention provides a refining method of p-phenylenediamine, which combines distillation and melting crystallization, uses the distillation product condensate to directly process melt crystallization for purification and processes fractional crystallization composed of one crystallization at least and one transpiration to obtain high-purity product. The invention combines distillation and melting crystallization to refine p-phenylenediamine and the invention can obtain high-purity and high-qaulity p-phenylenediamine product whose purity can reach 99.99-99.999% via controlling operation parameters, while the product quality can satisfy the quality demand of polymerization level product and the high-quality p-phenylenediamine can not be produced only by distillation. The refining method of p-phenylenediamine has the advantages of high product purity and flexible production set according to different standards, high yield of high-quality product and low cost, while the operation is processed without solvent to reduce pollution.

Description

(1) Technical field [0001] The invention relates to a method for refining p-phenylenediamine, in particular to a method for refining p-phenylenediamine used in the production of para-aramid fibers and imaging, etc., which require high quality. (2) Background technology [0002] P-phenylenediamine is a widely used intermediate, which can be used in the production of dyes, pigments, hair dyes, rubber anti-aging agents, para-aramid fibers, p-phenylenediisocyanate as a raw material for polyurethane production, etc. It is also commonly used to test iron and copper It is a sensitive reagent for gasoline polymerization inhibition and color photography coupling agent and other raw materials. [0003] Usually, p-phenylenediamine is obtained by reducing p-nitroaniline after amination of p-nitrochloroaniline. In order to obtain high-purity p-phenylenediamine raw materials, the p-phenylenediamine products obtained through reduction need to be purified and refined. The domestic traditio...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): C07C211/51C07C209/86
Inventor 何旭斌陶建国朱敬鑫苏建军罗镭彭文博吕赫
Owner 上海鸿源鑫创材料科技有限公司
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap