申请人:Asahi Kasei Chemicals Corporation
公开号:EP2088137A1
公开(公告)日:2009-08-12
An object of the present invention is to provide a process that enables isocyanates to be stably produced over a long period of time at high yield without encountering various problems as found in the prior art when producing isocyanates without using phosgene. The present invention discloses a process for producing an isocyanate, comprising the steps of: reacting a carbamic acid ester and an aromatic hydroxy compound to obtain an aryl carbamate having a group derived from the aromatic hydroxy compound; and subjecting the aryl carbamate to a decomposition reaction, wherein the aromatic hydroxy compound is an aromatic hydroxy compound which is represented by the following formula (1) and which has a substituent R1 at at least one ortho position of a hydroxyl group:
(wherein ring A represents an aromatic hydrocarbon ring in a form of a single or multiple rings which may have a substitute and which have 6 to 20 carbon atoms;
R1 represents a group other than a hydrogen atom in a form of an aliphatic alkyl group having 1 to 20 carbon atoms, an aliphatic alkoxy group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms or an aralkyloxy group having 7 to 20 carbon atoms, the group containing an atom selected from a carbon atom, an oxygen atom and a nitrogen atom; and R1 may bond with A to form a ring structure).
本发明的目的是提供一种工艺,使异氰酸酯能够长期稳定地高产生产,而不会遇到现有技术中在不使用光气生产异氰酸酯时发现的各种问题。本发明公开了一种生产异氰酸酯的工艺,包括以下步骤:使氨基甲酸酯和芳香族羟基化合物反应,得到芳基氨基甲酸酯,其基团来自芳香族羟基化合物;使芳基氨基甲酸酯进行分解反应,其中芳香族羟基化合物是由下式(1)表示的芳香族羟基化合物,在羟基的至少一个正交位置上具有取代基 R1:
(其中环 A 代表单环或多环形式的芳香烃环,可有取代基,具有 6 至 20 个碳原子;
R1 代表氢原子以外的基团,其形式为具有 1 至 20 个碳原子的脂肪族烷基、具有 1 至 20 个碳原子的脂肪族烷氧基、具有 6 至 20 个碳原子的芳基、具有 6 至 20 个碳原子的芳氧基、具有 7 至 20 个碳原子的芳烷基或具有 7 至 20 个碳原子的芳氧基,该基团含有选自碳原子、氧原子和氮原子的原子;且 R1 可与 A 结合形成环结构)。