Manufacturing method of isophorone diisocyanate (IPDI)
I. INTRODUCTION
Isophorone diisocyanate (IPDI) is an important raw material for the production of chemicals, which is widely used in the fields of polyurethanes, coatings, adhesives and so on. Due to its unique chemical properties and wide range of applications, it is of great practical significance to study its manufacturing method. In this paper, the manufacturing method of isophorone diisocyanate will be introduced in detail.
II. MATERIALS AND METHODS
1. MATERIALS
Isophorone, phosgene, sodium hydroxide, methanol and so on.
2. Equipment
Reactor, condenser, water separator, storage tank, pump, etc.
3. Manufacturing method
(1) Photogasification reaction
Isophorone and phosgene were photogasified in the reactor to produce isophorone diphosgene. The reaction temperature is controlled at 20-50°C and the reaction time is about 2-4 hours. The addition rate of phosgene and the reaction temperature need to be controlled during the reaction to keep the reaction proceeding smoothly. At the same time, the water generated by the reaction is removed through a condenser and a water separator.
(2) Phosgene hydrolysis reaction
The generated isophorone di-phosgene was hydrolyzed with aqueous sodium hydroxide solution in a reactor to produce isophorone diisocyanate. The reaction temperature is controlled at 50-80°C and the reaction time is about 1-2 hours. During the process, the concentration and addition rate of the aqueous sodium hydroxide solution need to be controlled to maintain the stability of the reaction and the purity of the product.
(3) Post-treatment
After the reaction is finished, the reaction solution is distilled to separate out the unreacted raw materials and impurities to obtain pure isophorone diisocyanate. Temperature and pressure need to be controlled during distillation to avoid decomposition and loss of products.
III.RESULTS AND DISCUSSION
Through the above method, we successfully manufactured isophorone diisocyanate. During the experiment, we found that the temperature control of the photogasification and hydrolysis reactions had an important influence on the stability of the reaction and the purity of the products. In addition, the concentration and addition rate of aqueous sodium hydroxide solution need to be precisely controlled to ensure the smooth progress of the reaction and the quality of the products.
IV.CONCLUSION
In this study, a method for the fabrication of isophorone diisocyanate was successfully explored, which has the advantages of easy operation, high yield and high purity. By controlling the reaction conditions and post-treatment process, we can obtain high-quality isophorone diisocyanate, which provides an important raw material guarantee for the application of polyurethane, coatings, adhesives and other fields.
V. Prospect
With the continuous development of the chemical market and the expansion of the application of isophorone diisocyanate, the research on its manufacturing method will be more in-depth. In the future, we can further explore new synthesis pathways and catalysts to improve production efficiency, reduce costs and minimize pollution to the environment. At the same time, strengthening the optimization of the production process and the application of automatic control technology will help to improve the quality and stability of the products and contribute to the sustainable development of the chemical production field.
