1, 4-cyclohexyl diisocyanate synthesis method

Abstract

The invention discloses a 1, 4-cyclohexyl diisocyanate synthesis method. The 1, 4-cyclohexyl diisocyanate synthesis method comprises the following steps that 1, solid triphosgene is dissolved in chloroform; the solution is cooled to a temperature of -5 to 0 DEG C; and 1,4-cyclohexanediamine is slowly and dropwisely added into the cooled solution; and 2, the mixed solution is heated to a temperature of 40 to 70 DEG C and undergoes a reaction for 6 hours; reaction products are cooled to a temperature of 10 to 20 DEG C and then are washed by an alkali until the reaction products are alkalescent; after the reaction products has a pH value of 7, chloroform is recovered; and 1, 4-cyclohexyl diisocyanate which is a faint yellow waxy solid is obtained by reduced pressure rectification. The 1, 4-cyclohexyl diisocyanate synthesis method has a simple synthesis route, avoids use of hypertoxic gas, and has a high product yield above 80% and high purity above 98.5%.

Description

technical field [0001] The invention relates to a method for synthesizing diisocyanate, in particular to a method for synthesizing 1,4-cyclohexane diisocyanate. Background technique [0002] Aliphatic and cycloaliphatic diisocyanates (ADI) are a class of specialty chemicals with -N=C=O functional groups, which are mainly used as raw materials for the manufacture of polyurethane materials. Polyurethane, which is formed by the addition polymerization of organic diisocyanate or polyisocyanate and dihydroxy or polyhydroxy compounds, can be used to manufacture plastics, rubber, fibers, rigid and flexible foams, adhesives and coatings. Diisocyanate molecules are important structural factors in the synthesis of polyurethane, and their different molecular structures directly affect the performance of polyurethane. 1,4-cyclohexane diisocyanate (1,4-cyclohexane disocyanate, CHDI for short) is a new type of diisocyanate with highly symmetrical and regular molecules, which can improve ...

AI Technical Summary

Problems solved by technology

[0003] In the 1980s, it was reported abroad that CHDI was used to synthesize polyurethane, but the synthesis process of CHDI has not been reported in China.

[0013] The synthesis route of this process is short, and the yield is about 70%, but this method needs to pass two kinds of gases, among them, phosgene is a kind of colorless and highly toxic gas, which has high requirements on the operating environment and serious pollution