Preparation process for xylylene diisocyanate

Abstract

The invention specifically discloses a preparation process for xylylene diisocyanate, which belongs to the technical field of synthetic materials. The preparation process comprises the following steps: 1, with bis(trichloromethyl)carbonate and hydrochloride in a mass ratio of 1: 1.5-3 as reaction raw materials, controlling temperature to be -10 to 40 DEG C, introducing carbon dioxide, carrying out stirring for 15 to 30 m, then carrying out cooling and adding an inertial organic solution; 2, heating a reaction solution for a reaction, wherein air pressure is 0.1 to 1 Mpa and heating temperature is 60 to 100 DEG C; and 3, subjecting a prepared reaction solution to pressure reduction, filtration and distillation so as to obtain xylylene diisocyanate. The preparation process for xylylene diisocyanate provided by the invention overcomes the problems of low processing and synthesis efficiency, low purity and a complex method in the prior art and can rapidly and easily process and synthesize xylylene diisocyanate with high purity; meanwhile, the price of equipment used in processing and synthesis is moderate, so needs for processing and synthesis of middle and small-sized enterprises are met, and production cost investment of the enterprises is reduced.

Description

technical field [0001] The invention relates to the technical field of synthetic materials, in particular to a preparation process for xylylene diisocyanate. Background technique [0002] As we all know, xylylene diisocyanate (XDI for short) is oxidized by mixed dibenzene (71% m-xylene and 29% p-xylene) and oxygen to form xylylene, and then hydrogenated and reduced to form xylylene Nitrile and then phosgenation, it is widely used in the processing and production of various coatings, resins, etc., and is the main chemical synthesis raw material. [0003] Existing xylylene diisocyanate synthesis generally adopts phosgenation method to make, and it consumes a lot of raw materials and the synthesis equipment price is expensive when it is synthesized on the one hand, and processing synthesis efficiency is low, purity is low, and synthesis reaction process is more complicated, not easy. There is a certain risk in the separation and preparation of excessive toxic phosgene; on the ...

AI Technical Summary

Problems solved by technology

[0003] Existing xylylene diisocyanate synthesis generally adopts phosgenation method to make, and it consumes a lot of raw materials and the synthesis equipment price is expensive when it is synthesized on the one hand, and processing synthesis efficiency is low, purity is low, and synthesis reaction process is more complicated, not easy. There is a certain risk in the separation and preparation of excessive toxic phosgene; on the other hand, the equipment used in the synthesis is expensive, and the production cost is high, which cannot meet the needs of small and medium-sized enterprises for processing and synthesis.