CPC C07C 263/20 (2013.01) [C07C 265/14 (2013.01)] | 2 Claims |
1. A process for preparing a diisocyanate composition, which comprises:
obtaining a diamine hydrochloride composition by reacting diamine with an aqueous hydrochloric acid solution and then adding a first organic solvent; and
obtaining a diisocyanate composition by reacting the diamine hydrochloride composition with triphosgene,
wherein the diamine hydrochloride composition has a b* value of 1.2 or less according to the CIE color coordinate when dissolved in water at a concentration of 8% by weight,
wherein the step of obtaining the diisocyanate composition further comprises step B for treating the diamine hydrochloride composition after the diamine hydrochloride composition is obtained,
wherein step B for treating the diamine hydrochloride composition comprises washing the diamine hydrochloride composition with a solvent having a polarity index of 5.7 or less,
wherein in the step of washing the diamine hydrochloride composition, the b* value according to the CIE color coordinate of the diamine hydrochloride composition is adjusted,
wherein the first organic solvent and the solvent having a polarity index of 5.7 or less are different, and
wherein the solvent having a polarity index of 5.7 or less comprises dichloromethane.
|