Production of isocyanates
US4029686A · kind A · utility
2Cited by
1References
7Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 8, 1975 |
| Grant date | Jun 14, 1977 |
| Priority date | — |
| Expiry date | Dec 8, 1995 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C2602/22
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A furoxan, especially one in which the furoxan ring is fused to a strained aliphatic ring system, is heated in the presence of sulphur dioxide to give an isocyanate. The process enables furoxans, such as dicyclopentadiene furoxan, which ring-open at temperatures <180.degree. C to be converted into isocyanates. In the absence of sulphur dioxide, may be difficult to control the reaction and, in some cases, no isocyanate is obtained. Diisocyanates prepared by the process may be converted into polyurethanes by reaction with suitable hydroxylic compounds.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.