Preparation of aromatic polyisocyanates in gaseous phase
US5679839A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 14, 1995 |
| Grant date | Oct 21, 1997 |
| Priority date | — |
| Expiry date | Aug 14, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P20/582
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
Aromatic polyisocyanates are prepared by reacting at least one compound (A), containing at least two primary amine functions and at least one aromatic nucleus, with a relatively modest quantity of phosgene, in the gaseous phase, the amount of phosgene ranging from the stoichiometric amount to a stoichiometric excess of 100% with respect to the number of moles of amine functions of compound (A), carried out in a mixed reactor which comprises a first, homogenizing zone constituting from 20% to 80% of the total volume thereof, and a second, essentially piston flow downstream zone constituting from 80% to 20% of the total volume thereof.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.