Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Method for preparing p-phenylenediamine

A technology of p-phenylenediamine and p-nitroaniline, which is applied in the field of preparation of p-phenylenediamine, can solve the problems of low purity of p-phenylenediamine, excessive industrial wastewater, and environmental pollution, and achieve simple and safe production process with less pollution , the effect of reducing production costs

Inactive Publication Date: 2019-04-19
安徽高盛化工股份有限公司
View PDF8 Cites 5 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The biggest defect of this process is that there is a lot of industrial waste water, iron powder reduction will also produce a large amount of iron sludge, which seriously pollutes the environment, and the purity of p-phenylenediamine produced by this process is relatively low, generally around 95%. For the current environmental protection needs, this This traditional production process can no longer adapt to

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 preparing p-phenylenediamine
  • Method for preparing p-phenylenediamine
  • Method for preparing p-phenylenediamine

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] A preparation method of p-phenylenediamine, specifically comprising the following steps:

[0026] S1: Take a certain amount of p-nitroaniline, hydrogen, deionized water and a new type of hydrogenation nickel catalyst by weight, in which water is used as a solvent, hydrogen participates in the reaction and is excessive, and p-nitroaniline is ground by a grinder in advance, and the p-nitroaniline The mass ratio of nitroaniline to water is 1:3, the new nickel hydrogenation catalyst accounts for 2.6% of the mass of p-nitroaniline, and the mass ratio of p-nitroaniline to hydrogen is not more than 1 / 3. Nitroaniline takes 1.38kg, wherein in this application, the relative molecular mass of p-nitroaniline is 138, and the molecular mass of p-phenylenediamine phase is 108;

[0027] S2: Put p-nitroaniline, water and a new nickel hydrogenation catalyst into the reaction kettle, and replace the air in the reaction kettle with nitrogen. About 1MPa, the number of replacements with nit...

Embodiment 2

[0042] On the basis of embodiment 1, other parameters are constant, change the reaction time of step S3, i.e. the value of h, wherein h takes the value of 3 hours, brings in the formula (a), can get δ greater than 1, then proves that to nitric acid The conversion rate of phenylenediamine reaches 100%, and the yield of p-phenylenediamine is 1.069kg, then the yield is 1.069 / 1.08=98.98%, and by gas chromatograph analysis, the purity of p-phenylenediamine exceeds 99.914%; It can be seen that the phase Compared with Example 1, the yield and purity of p-phenylenediamine in Example 2 are slightly improved; the actual conversion rate of p-nitroaniline calculated by gas chromatograph analysis is 100%, which is the same as the calculation result of the formula.

[0043] If the reaction time is lower than 2 hours, it is brought into the formula (a), and the obtained δ is 49.5%. For example, the reaction time is 1 hour, and the yield of p-phenylenediamine is 0.956kg, then the yield is 0.95...

Embodiment 3

[0046] On the basis of Example 1, other parameters remain unchanged, and ΔT is changed, wherein ΔT takes a value of 10°C, that is, the reaction temperature of 60°C in step S3 is increased to 70°C, so that the reaction is carried out at 70°C. Bring in the formula (a), can get δ greater than 1, then prove that the conversion rate of p-nitroaniline reaches 100%, the yield of p-phenylenediamine is 1.071kg, then yield is 1.071 / 1.08=99.16%, by According to gas chromatography analysis, the purity of p-phenylenediamine is 99.916%; the actual conversion rate of p-nitroaniline calculated by gas chromatograph analysis is 100%, which is the same as the formula calculation result.

[0047]If the reaction temperature is lower than 60°C, it is brought into the formula (a), and the obtained δ is less than 1, which proves that the conversion rate of p-nitroaniline decreases. For example, the reaction temperature is 40°C, and the conversion rate is 66% calculated by the formula. The yield of ph...

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 discloses a method for preparing p-phenylenediamine. A reduction reaction is carried out on paranitroaniline with hydrogen in the presence of a catalyst. According to the preparation method, the temperature, pressure and reaction time in the reduction reaction are controlled, and the conversion rate of p-phenylenediamine is controlled. According to the method, a hydrogenation reduction production mode is adopted, environment-friendly production is achieved, pollution is low, the conversion rate of paranitroaniline is increased, and high-purity p-phenylenediamine is obtained.

Description

technical field [0001] The invention relates to the technical field of production technology of p-phenylenediamine, in particular to a preparation method of p-phenylenediamine. Background technique [0002] P-phenylenediamine is an important organic intermediate widely used in dyestuff, rubber, national defense and other industries. In the dye industry, azo dyes and fur dyes can be produced; in the rubber industry, rubber anti-aging agents can be produced. The traditional production process of p-phenylenediamine is that p-nitroaniline is reduced by alkali sulfide or iron powder to produce crude p-phenylenediamine, and finally purified by recrystallization to obtain high-purity p-phenylenediamine. The biggest defect of this process is that there is a lot of industrial waste water, iron powder reduction will also produce a large amount of iron sludge, which seriously pollutes the environment, and the purity of p-phenylenediamine produced by this process is relatively low, gen...

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
Patent Type & Authority Applications(China)
IPC IPC(8): C07C209/36C07C211/51
CPCC07C209/36C07C211/51
Inventor 屈学勇
Owner 安徽高盛化工股份有限公司
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

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

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com