UN METODO PARA PRODUCIR ISOCIANATOS A PARTIR DE ESTERES DE ACIDOS CARBAMICOS.

摘要

In the method for the production of isocyanates from esters of carbamic acids (urethanes) by thermally decomposing said ester while said ester is dissolved in a suitable inert reaction medium solvent to produce the isocyanate and alcohol and removing the isocyanate and alcohol and a carrier agent and separately recovering the isocyanate, alcohol and carrier, the improvement which comprises recovering said reaction medium solvent together with any isocyanate and urethane values contained therein by stripping said solvent and the isocyanate/urethane values from the reactor bottoms away from any heavy by-product residues present in the reactor bottoms effluent. Inert stripping solvents or inert gases or mixtures of gas and solvent are used as the stripping medium and include the solvents, gases or mixtures thereof employed as carrier agents and are preferably the same recovered carrier agents employed during the thermal decomposition reaction.