| 摘要 |
A method for manufacturing tolylene diisocyanate comprises a mixing step, a carbamate manufacturing step, and a pyrolysis step. In the mixing step, a first diaminotoluene containing 2,4- and 2,6-diaminotoluene in a first isomeric ratio is mixed with a second diaminotoluene containing 2,4- and/or 2,6-diaminotoluene in a second isomeric ratio, and mixed diaminotoluene is prepared. In the carbamate manufacturing step, a reaction is brought about between the mixed diaminotoluene prepared in the mixing step, urea and/or N-unsubstituted carbamate, and an alcohol, whereby tolylene dicarbamate is produced. In the pyrolysis step, the tolylene dicarbamate is pyrolyzed. |
