PROCESS OF PREPARING XYLYLENE DIISOCYANATES, THEIR REACTION INTERMEDIATES AND PROCESS OF PREPARING THEM

摘要

PURPOSE: A manufacturing method of xylene diisocyanate is provided to able to manufacture a non-yellowing type m-xylylene diisocyanate without using phosgene manufactured which has strong toxicity and strong causticity. CONSTITUTION: A manufacturing method of xylene diisocyanate comprises: a step of preparing biscarbamate in chemical formula 3 by reacting a diamine compound in chemical formula 1 with alkyl chloroformate in chemical formula 2 or dialkyl carbonate in; and a step of decomposing and removing alcohol of relatively low boiling point by heat-decomposing the biscarbamate. In the chemical formulas, Rx is a halogenated alkyl group. The heat decomposition is conducted under the presence of a solvent.