[EN] PROCESS FOR THE PREPARATION OF ISOCYANATES<br/>[FR] PROCÉDÉ DE PRÉPARATION D'ISOCYANATES
申请人:COVESTRO DEUTSCHLAND AG
公开号:WO2019145380A1
公开(公告)日:2019-08-01
The invention relates to a process for the preparation of aliphatic, cycloaliphatic or araliphatic isocyanates by reacting at least one primary organic amine with a stoichiometric excess of phosgene in the gas phase, comprising the steps a) reaction of the primary organic amine with an excess of phosgene in the gas phase and quenching the process product with a liquid comprising an inert aromatic solvent to obtain a liquid stream containing the isocyanate and a gas stream containing HCl and phosgene, b) separation of the gas stream containing HCl and phosgene obtained in step a) into a gas stream containing HCl and a liquid stream containing phosgene, c) partial vaporization of the liquid stream containing phosgene obtained in step b) to produce a gas stream containing phosgene, d) the gas stream containing phosgene obtained in step c) is at least partially recycled into the reaction in step a), and wherein the gas stream containing phosgene obtained in step c) contains 0.5 wt% or less of the sum of benzene, chlorobenzene and dichlorobenzene. The invention additionally relates to an isocyanate composition.
本发明涉及一种通过气相中至少一种一级有机胺与计量过量的光气反应来制备脂肪族、环脂肪族或芳脂肪族异氰酸酯的过程,包括以下步骤:a) 一级有机胺与过量的光气在气相中反应,并且用含有惰性芳香溶剂的液体淬灭过程产物,以获得含有异氰酸酯的液体流和含有氯化氢和光气的气体流;b) 将步骤a)中获得的含有氯化氢和光气的气体流分离成含有氯化氢的气体流和含有光气的液体流;c) 部分汽化步骤b)中获得的含有光气的液体流,以产生含有光气的气体流;d) 将步骤c)中获得的光气气体流至少部分地循环回到步骤a)中的反应中;并且其中,步骤c)中获得的光气气体流含有0.5重量%或以下的苯、氯苯和二氯苯的总和。本发明还涉及一种异氰酸酯组合物。