Aged molten color of maleic anhydride
US4260546A · kind A · utility
6Cited by
2References
4Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 26, 1979 |
| Grant date | Apr 7, 1981 |
| Priority date | — |
| Expiry date | Dec 26, 1999 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C51/573
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
The oxidation of butane vapor with air produces an impure maleic anhydride which when fractionated to first remove materials boiling lower than maleic anhydride and then a maleic anhydride product, leads to a maleic anhydride product fraction which when held at 140.degree. C. for 90 minutes discolors and is not a commercially acceptable product. Such discoloration can be substantially reduced by maintaining the impure maleic anhydride at a temperature from 60.degree. up to 200.degree. C. in the presence of small amounts of either hydrogen peroxide and/or sulfuric acid.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.