Method for preparing isocyanates by liquid-phase thermal cracking
US8809574B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 14, 2009 |
| Grant date | Aug 19, 2014 |
| Priority date | — |
| Expiry date | Aug 15, 2031 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01J23/755
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
The present invention discloses a method for preparing isocyanates by liquid-phase catalytic thermal cracking. In this method, in a reaction-rectification thermal cracking reactor, using a catalyst composition comprising a superfine powder metal oxide catalyst and an ionic liquid, an alkyl or aryl dialkylurethane, or multialkylurethane being a reactant is liquid-phase thermal cracked for a reaction time of 0.5-3 h under a reaction temperature of 160-220° C. and an absolute pressure of 1000-8000 Pa so as to prepare the corresponding isocyanate. The invention has the characteristics of low thermal cracking temperature, high yield of target products, relatively simple reaction apparatus and good universality for substrates (the yields of HDI, MDI, TDI, HMDI, NDI and IPDI or the like are all>85%) and the like.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.