System integrating fatty group or ring group diisocyanate synthesis and separation and purification and synthesis method

Abstract

The invention discloses a system integrating fatty group or ring group diisocyanate synthesis and separation and purification and a synthesis method. The system comprises a wiped film vaporizer, a first rectifying tower, a second rectifying tower, a first heat exchanger and a second heat exchanger; the wiped film vaporizer is communicated with the first rectifying tower through a pipe, an outlet pipe of the first rectifying tower is communicated with the middle of the second rectifying tower, the bottom of the second rectifying tower is communicated with the first heat exchanger, and the top of the second rectifying tower is communicated with the second heat exchanger. By means of the system integrating fatty group or ring group diisocyanate synthesis and separation and purification, components generated by pyrolysis can be separated efficiently, and the system is quite suitable for a heat sensitivity material system; by the adoption of the system, materials which do not react completely are returned to a reactor for continuous pyrolysis, a diisocyanate product and light components are subjected to extraction with the rectifying towers, a coarse product is high in purity, energy is saved, consumption is reduced, and the diisocyanate product is good in selectivity and high in yield.

Description

technical field [0001] The invention belongs to the field of organic chemical industry, and relates to a preparation method of a chemical intermediate, specifically, to a system integrating the synthesis, separation and purification of aliphatic or cyclic diisocyanate and the synthesis of aliphatic or cyclic diisocyanate by using the system Diisocyanate method. Background technique [0002] As a class of important organic reaction intermediates, isocyanates are widely used in industry, agriculture, medicine and health. Isocyanates that are widely used in industry generally contain two or more -N=C=O functional groups. Among them, aliphatic (cyclic) diisocyanates are yellowing-resistant diisocyanates, which are mainly used in automotive coatings and repair paints, aircraft Coatings and repair paints, anti-corrosion paints, wooden furniture paints, enameled wire paints, train repair paints, polyurethane adhesives with good light stability and rocket propellants, etc. [0003...

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Problems solved by technology

[0008] The purpose of the present invention is to solve the problem of low yield and low conversion rate of aliphatic or cyclic dicarbamate synthesized by continuous thermal decomposition of aliphatic or cyclic diisocyanate, and to provide a process integrating synthesis, separation and purification System, which has the advantages of simple process, high reaction efficiency, mild conditions, short reaction time, easy separation of products and high quality, recycling of by-products and solvents, and environmentally friendly process

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