用碳酸二甲酯代替光气合成甲苯二异氰酸酯Ⅱ.甲苯二氨基甲酸甲酯的分解

Synthesis of Tolylene Diisocyanate with Dimethyl Carbonat e Instead of Phosgene Ⅱ.Cleavage of Tolylene Dicarbamate

在对于甲苯二氨基甲酸甲酯 (TDC)分解反应系统进行分析的基础上 ,设计并安装了分解反应装置。实验结果表明 :TDC分解的最佳热载体为癸二酸二辛酯 ;最佳混合溶剂为“四氢呋喃 +硝基苯” ;适宜的反应条件是 2 5 0～ 2 70℃ ,2 .6 6 6kPa。热分解的甲苯二异氰酸酯 (TDI)最高产率为 85 5 % ,而催化分解的TDI最高产率为 92 6 %。

On the basis of studying the cleavage reaction of t ol ylene dicarbamate (TDC) to tolylene diisocyanate (TDI),the apparatus used for th is reaction was designed and assembled.Effects of reaction solvents,heat -carriers and catalysts on the cleavage reaction were investigated and much higher TDI yield was obtained:the highest yield from thermal cleavage was 85.5% while that from catalytic cleavage was 92.6%.