	US 11,731,936 B2
	Diisocyanate composition, preparation method thereof and optical material using same
Jaeyoung Pai, Gyeonggi-do (KR); Jeongmoo Kim, Gyeonggi-do (KR); Jung Hwan Myung, Gyeonggi-do (KR); Hyuk Hee Han, Gyeonggi-do (KR); Jooyoung Jung, Gyeonggi-do (KR); and Myung-Ok Kyun, Gyeonggi-do (KR)
Assigned to SKC CO., LTD., Gyeonggi-do (KR); and WOORI FINE CHEM CO., LTD, Gyeonggi-do (KR)
Filed by SKC CO., LTD., Gyeonggi-do (KR); and WOORI FINE CHEM CO., LTD., Gyeonggi-do (KR)
Filed on Dec. 4, 2020, as Appl. No. 17/111,857.
Claims priority of application No. 10-2019-0161537 (KR), filed on Dec. 6, 2019; application No. 10-2019-0162101 (KR), filed on Dec. 6, 2019; application No. 10-2020-0045442 (KR), filed on Apr. 14, 2020; and application No. 10-2020-0054559 (KR), filed on May 7, 2020.
Prior Publication US 2021/0171448 A1, Jun. 10, 2021
Int. Cl. C07C 263/20 (2006.01); G02B 1/04 (2006.01); C08G 18/38 (2006.01); C08G 18/75 (2006.01); C07C 265/14 (2006.01)

CPC C07C 263/20 (2013.01) [C08G 18/3868 (2013.01); C08G 18/757 (2013.01); G02B 1/041 (2013.01); C07C 265/14 (2013.01)]

11 Claims

1. 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; and

(2) reacting the diamine hydrochloride composition with triphosgene in an organic solvent to obtain a diisocyanate composition,

wherein, a content of water, or a content of an aromatic compound containing 3 or more of chlorine (Cl) in the organic solvent is adjusted,

wherein further comprising measuring a total content of cations in the organic solvent before the reaction, wherein, if the total content of cations in the organic solvent exceeds 5 ppm, the organic solvent is purified and then used in the reaction,

and wherein, when the organic solvent is purified, the content of cations in the organic solvent is adjusted.