Patent ID: 11964931
Assignee: WOORI FINE CHEM CO., LTD.
Field: Organic fine chemistry (Chemistry)
Classification: CPC B  C  G  Y | IPC B  C  G

Claim 7:
8. A process for preparing a diisocyanate composition, which comprises:
(1) reacting a diamine with an aqueous hydrochloric acid solution to obtain a diamine hydrochloride composition;
(2-1) reacting the diamine hydrochloride composition with triphosgene to obtain a crude diisocyanate composition; and
(2-2) distilling the crude diisocyanate composition at a temperature of 100° C. to 130° C. to obtain a diisocyanate composition,
wherein the reaction of the diamine hydrochloride composition and triphosgene of step (2-1) sequentially comprises:
(2-a) mixing the diamine hydrochloride composition with an organic solvent to obtain a first solution;
(2-b) mixing triphosgene with the organic solvent to obtain a second solution; and
(2-c) introducing the second solution to the first solution and stirring them, wherein the introduction of the second solution and stirring is carried out at a temperature of 115° C. to 160° C., and
the organic solvent is introduced to the reaction in an amount of 4.2 to 4.8 times the weight of the diamine hydrochloride composition, or
the organic solvent is introduced to the reaction in an amount of 0.6 to 0.9 times the weight of the triphosgene.