Patent ID: 8748654
Filing Date: 2014-06-10
Classification: C07C

Abstract:
1. A method for producing tolylene diisocyanate containing 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate at a target isomer ratio, the method comprising: mixing a first diaminotoluene containing 2,4-diaminotoluene and 2,6-diaminotoluene at a first isomer ratio and a second diaminotoluene containing 2,4-diaminotoluene and/or 2,6-diaminotoluene at a second isomer ratio that is different from the first isomer ratio so as to prepare mixed diaminotoluene; producing tolylene dicarbamate by reaction of the mixed diaminotoluene, urea and/or N-unsubstituted carbamic acid ester and alcohol; and thermally decomposing the tolylene dicarbamate.