申请人:Shinohata Masaaki
公开号:US20100029981A1
公开(公告)日:2010-02-04
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 R
1
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;
R
1
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 R
1
may bond with A to form a ring structure).
本发明的目的是提供一种过程,使得在不使用光气的情况下,能够稳定地高产长时间生产异氰酸酯,而不会遇到生产异氰酸酯时在先前技术中发现的各种问题。本发明公开了一种生产异氰酸酯的方法,包括以下步骤:反应一个氨基甲酸酯和一个芳香羟基化合物以获得含有源自芳香羟基化合物的基团的芳基氨基甲酸酯;并将芳基氨基甲酸酯进行分解反应,其中芳香羟基化合物是由以下式(1)表示并且在羟基位置的至少一个邻位上具有取代基R1的芳香羟基化合物:(其中,环A表示一个具有单个或多个环,并且可能具有取代基的芳香烃环,其具有6至20个碳原子;R1表示除氢原子外的基团,以具有1至20个碳原子的脂肪基烷基团,具有1至20个碳原子的脂肪基烷氧基团,具有6至20个碳原子的芳基团,具有6至20个碳原子的芳氧基团,具有7至20个碳原子的芳基烷基团或具有7至20个碳原子的芳基烷氧基团,该基团含有从碳原子、氧原子和氮原子中选择的原子;并且R1可以与A结合形成一个环状结构)。