Method of preparing diisocyanate composition and optical lens
US11964931B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Dec 2, 2020 |
| Grant date | Apr 23, 2024 |
| Priority date | — |
| Expiry date | Jun 5, 2042 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P20/582
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
In the embodiments, an aqueous hydrochloric acid solution instead of hydrogen chloride gas and solid triphosgene instead of phosgene gas may be used in the process of preparing a diisocyanate from a diamine through a diamine hydrochloride. In addition, the embodiments provide processes for preparing a diisocyanate composition and an optical lens of higher quality, in which the reaction temperature of a diamine hydrochloride composition and triphosgene is controlled to a specific range, or a crude diisocyanate composition obtained from the reaction of a diamine hydrochloride composition and triphosgene is distilled at a specific temperature range, or the molar ratio of a diamine hydrochloride and triphosgene is adjusted to a specific range.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.