Preparation and recovery of methacrylic acid from an aqueous sodium methacrylate solution
US4180681A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 17, 1978 |
| Grant date | Dec 25, 1979 |
| Priority date | — |
| Expiry date | Aug 17, 1998 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C51/42
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process for the recovery of methacrylic acid formed from an aqueous sodium methacrylate solution derived from the silver catalyzed oxidation reaction of methacrolein and an aqueous solution of sodium hydroxide which comprises contacting the aqueous sodium methacrylate solution at a suitable temperature, in the presence of a high gaseous carbon dioxide pressure, with a water immiscible alkane, cycloalkane, alkyl benzene, or carboxylic acid ester solvent to extract and form a methacrylic acid-containing organic solvent phase, an aqueous phase and a precipitated sodium bicarbonate solid phase and recovering the methacrylic acid from the organic solvent phase. Liquid CO.sub.2 which may be employed with the water immiscible solvent at 800 psig may also be employed alone at its equilibrium vapor pressure as the reactant and extractant medium.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.