Method for preparing isocyanate in gaseous phase
US11814339B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Dec 26, 2018 |
| Grant date | Nov 14, 2023 |
| Priority date | — |
| Expiry date | Dec 26, 2038 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C265/06
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A method for preparing an isocyanate in a gaseous phase by feeding, in the presence or absence of an inert gas, an amine-containing gas stream and a phosgene-containing gas stream into a reaction region, allowing the amine and the phosgene to contact in gaseous forms and undergo a phosgenation reaction in the reaction region, thus preparing the target isocyanate in a gaseous form in the reaction region. The phosgene-containing stream is subjected to preheating and warming before being fed into the reaction region, and the phosgene-containing stream comprises a substance A at a mass fraction of <1% before being subjected to the preheating and warming up. Substance A is a NCO group-containing substance and/or an olefinic double bond-containing substance. The method reduces the formation of clogging matter in a heat exchanger and a vessel during the preheating and warming of the phosgene and during the reaction process.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.