PURPOSE: To industrially advantageously produce the subject compound by reacting an aromatic amine compound with an excessive amount of phosgene in an inert solvent by two steps under specific conditions to reduce the contents of acids and hydrolyzable chlorine atoms in the obtained aromatic isocyanate compound.
CONSTITUTION: An aromatic amine compound such as methylene-crosslinked polphenylene polyamine containing diaminodiphenylmethane in an amine concentration of 1-30% is subjected to the first step reaction using phosgene in an amount of 5-20 times moles based on the amine in an inert solvent such as ortho-dichlorobenzene at 0-90°C for 10-120min under a pressure of ≤10kg/cm2, and subsequently subjected to the second step reaction using an excessive amount of the phosgene at 100-150°C for 10-120min under a pressure of ≤10kg/cm2, while the phosgene and hydrogen chloride gases in amounts of 0.5-10 time moles and 0.2-20 time moles, respectively, based on the amine are fed into the reaction solution, thus providing the objective compound useful for producing polyurethane foams, elastomers, adhesives, etc.
| WO/2003/035606 | IMPROVED METHOD FOR PRODUCING ISOCYANATES |
| JPS6391355 | DIISOCYANATE, MANUFACTURE AND USE |
| WO/2010/021334 | METHOD FOR PRETREATMENT FOR PRODUCTION OF ISOCYANATE MIXTURE |
TAJIMA JUNJI
NAGO TAKU
NITTA KAZUNARI
YANO NAOYUKI
NAGAYOSHI TATSUYA
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