Method for producing tolylene diisocyanate
AssigneeMitsui Chemicals, Inc.
InventorsKoji Takamatsu, Kazuhiro Kosumi, Takeshi Fukuda, Masaaki Sasaki
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Abstract
A method for producing tolylene diisocyanate includes: 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.
Claims3
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.
Dependencies are inferred from the claim text.