Process for the purification of O,O-di(lower)alkyldithiophosphoric acids
US4209471A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 10, 1977 |
| Grant date | Jun 24, 1980 |
| Priority date | — |
| Expiry date | May 10, 1997 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07F9/025
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A liquid-liquid extraction method for recovering O,O-di(lower)alkyldithiophosphoric acid of increased purity from a crude mixture in which it is contained comprises intimately contacting said mixture with an acidic aqueous solution to form two liquid phases whereby the concentration of the thiophosphoric acid in the aqueous phase is increased; separating the two phases; contacting the aqueous phase with a stable, water-immiscible, volatile, organic solvent to form two liquid phases whereby the concentration of the thiophosphoric acid in the organic solvent is increased; separating the two phases; and vaporizing the organic solvent to recover high purity O,O-di(lower)alkyl dithiophosphoric acid.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.