Method of preparing diisocyanate composition
AssigneesSkc Co., Ltd., Woori Fine Chem Co., Ltd.
InventorsJaeyoung Pai, Jeongmoo Kim, Jung Hwan Myung, Hyuk Hee Han
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Abstract
The embodiments provide processes for preparing a diisocyanate composition and an optical lens, which are excellent in yield and quality with mitigated environmental problems by using a solid triphosgene composition instead of phosgene gas in the process of preparing a diisocyanate from a diamine through a hydrochloride thereof and by controlling the content of a decomposition product in a triphosgene composition, the b* value according to CIE color coordinate of the triphosgene composition in an organic solvent, or the content of water in the triphosgene.
Claims6
A process for preparing a diisocyanate composition, which comprises:
- reacting a diamine hydrochloride composition with a triphosgene composition to obtain a diisocyanate composition,
- wherein the triphosgene composition has a b* value according to the CIE color coordinate of 1.2 or less when dissolved in orthodichlorobenzene at a concentration of 8% by weight, and
- wherein the b* value according to the CIE color coordinate of the triphosgene composition is adjusted by washing the triphosgene composition with a 10% to 30% sodium chloride solution.
Dependencies are inferred from the claim text.