CPC C07C 265/14 (2013.01) [C07C 263/10 (2013.01); C07C 263/20 (2013.01); C08G 18/7642 (2013.01); G02B 1/041 (2013.01)] | 6 Claims |
1. A process for preparing a diisocyanate composition for an optical lens, the process comprising:
reacting a diamine with an aqueous hydrochloric acid solution to obtain a diamine hydrochloride composition; and
obtaining a diisocyanate composition from the diamine hydrochloride composition by a phosgenation reaction,
wherein a process for preparing the diamine hydrochloride composition comprises a sequence of:
(1a) introducing an aqueous hydrochloric acid solution into a first reactor;
(1b) introducing and stirring a diamine into the first reactor; and
(1c) introducing and stirring a first organic solvent into the first reactor,
wherein the aqueous hydrochloric acid solution is introduced such that the amount of HCl is 2.02 moles to 4.00 moles per 1 mole of the diamine, and
the diamine hydrochloride composition has a pH of 3.0 to 4.0 when dissolved in water at a concentration of 10% by weight,
wherein the content of chlorine ions in the diisocyanate composition is 100 ppm or less,
wherein the process further comprises treating the diamine hydrochloride composition after the diamine and the aqueous hydrochloric acid solution are reacted, and
wherein the step of treating the diamine hydrochloride composition comprises at least one of precipitating the diamine hydrochloride composition, filtering the diamine hydrochloride composition, drying the diamine hydrochloride composition, and washing the diamine hydrochloride composition.
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