Method for removal of phenothiazine inhibitor from acrylic acid
US5763658A · kind A · utility
3Cited by
13References
20Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Oct 18, 1995 |
| Grant date | Jun 9, 1998 |
| Priority date | — |
| Expiry date | Oct 18, 2015 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C51/47
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process for decreasing the concentration of phenothiazine from a solution of acrylic acid by contacting the acrylic acid solution with a hydrophobic clay, such as an organophilic clay; or by protonating the phenothiazine, oxidizing the phenothiazine, and contacting the protonated, oxidized phenothiazine with a hydrophilic clay, such as an acid-activated smectite clay or sodium bentonite clay to sorb (absorb and/or adsorb) the phenothiazine into or onto the clay. Once sorbed onto the smectite clay, the phenothiazine easily can be removed, together with the clay, from the solution of acrylic acid, e.g., by filtration.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.